Is Anything Too Hard for the LORD?

Read Genesis 17 and Genesis 18 in full before proceeding. Keep your Bible open throughout this session.

Is anything impossible for the LORD?

— Genesis 18:14

Genesis 17 and Genesis 18 form a pair. They give us, in sequence, the deepening of the Abrahamic covenant. The LORD has appeared to Abram several times now — in Haran, at Shechem, at Bethel, between the divided animals in the great covenant ceremony of Genesis 15. He has spoken; He has promised; He has cut covenant. The promise has been moving toward its fulfillment, but the seed-line still hangs by the thread of Sarai’s barrenness. Ishmael has been born. Thirteen years have passed since Ishmael’s birth. Abraham is now ninety-nine. Sarah is approaching ninety. The natural means of producing the promised seed are not just delayed; they are biologically closed.

And then the LORD appears again.

Two chapters cover what happens next. Genesis 17 gives us the covenant deepened and specified: a new divine name (El Shaddai), a new sign for the covenant (circumcision in the flesh), new names for Abraham and Sarah, and an explicit promise that the son of the covenant will come through Sarah specifically. Genesis 18 then brings three visitors to the oaks of Mamre — visitors who turn out to include the LORD Himself — for a remarkable meal of hospitality, a definite promise that Sarah will bear a son within the year, and the most extended intercession of the patriarchal narrative as the LORD discloses His judgment on Sodom and Abraham bargains for the city.

Two questions hold the chapters together. In Genesis 17, when Abraham laughs at the promise of a son, the LORD asks (in effect): is anything too hard? In Genesis 18, when Sarah laughs at the same promise, the LORD asks it explicitly: Is anything too hard for the LORD? And in the second half of Genesis 18, when Abraham learns of Sodom’s coming judgment, he asks the LORD: Shall not the Judge of all the earth do right? The two questions, in the two chapters, frame the session. Is the LORD strong enough to keep His promise? Is the LORD just in His judgment?

The chapters answer both.

El Shaddai

When Abram was 99 years old, the LORD appeared to him and said, “I am the Sovereign God. Walk before me and be blameless. Then I will confirm my covenant between me and you, and I will give you a multitude of descendants.” Abram bowed down with his face to the ground, and God said to him, “As for me, this is my covenant with you: You will be the father of a multitude of nations. No longer will your name be Abram. Instead, your name will be Abraham because I will make you the father of a multitude of nations. I will make you extremely fruitful. I will make nations of you, and kings will descend from you. I will confirm my covenant as a perpetual covenant between me and you. It will extend to your descendants after you throughout their generations. I will be your God and the God of your descendants after you. I will give the whole land of Canaan—the land where you are now residing —to you and your descendants after you as a permanent possession. I will be their God.”

The LORD identifies Himself by a new name. I am God Almighty. The Hebrew is El Shaddai. The meaning of Shaddai is debated among scholars. Some derive it from shadad, to overpower; others from shadu, the Akkadian word for mountain (giving “God of the mountain”); others from shad, breast (giving the sense of God as nourisher and provider). The traditional rendering — Almighty — captures the central thrust: this is the all-sufficient, all-powerful God, before whom no human limit can finally stand.

The timing of this name is theologically significant. Abraham is ninety-nine. Sarah is ninety (Genesis 17:17). The biological window for childbearing has closed. By any natural reckoning, the promise of a son through Sarah has become impossible. And in this exact moment — when the question becomes whether anything could overcome the natural impossibility — the LORD identifies Himself as El Shaddai. The Almighty One. The God whose power is not constrained by the limits of natural process. The God who can do, in human flesh, what cannot be done in human flesh.

This name will recur in the Old Testament at moments when the LORD’s power is invoked against impossible circumstances. Isaac will bless Jacob “by God Almighty” (Genesis 28:3). Jacob will recall the appearance of “God Almighty” when speaking to his sons (Genesis 48:3). The name carries this freight: the LORD whose power makes possible what cannot otherwise be done.

Walk before me, and be blameless. The covenant has a moral expectation. Abram is called to a specific quality of life — to walk before the LORD (in His presence, with His eyes on him) and to be blameless (Hebrew tamim, whole, complete, having integrity). This is not works-righteousness; the covenant is established by the LORD’s grace, not by Abram’s blamelessness. But the covenant relationship calls for a corresponding life. The LORD’s people are to walk in the LORD’s presence with integrity. This is what we would today call the sanctified life — the life that flows out of justification. The LORD has counted Abram righteous (Genesis 15:6); now He calls Abram to live in a manner consistent with what he is.

“As for me, this is my covenant with you: You will be the father of a multitude of nations.

The covenant is deepened. The promise of nation (singular, Genesis 12:2) is expanded to nations (plural). Abraham will be the father not just of Israel but of multiple peoples — Israel through Isaac and Jacob, the Edomites through Esau, the Ishmaelite peoples through Ishmael, the Midianites through Keturah’s sons after Sarah’s death, and (in the deeper Pauline reading) all Gentile believers who share Abraham’s faith. The scope is universal.

And the name change makes this explicit. No longer shall your name be called Abram, but your name shall be Abraham. Abram means exalted father. Abraham — the addition of the h sound — is understood by the biblical text to mean father of a multitude (av-hamon in Hebrew). The new name is the prophetic name. Abraham’s identity is now defined by what the LORD has promised to do through him. He is not just an exalted father within his own clan; he is the father of multitudes that will arise from him.

Kings shall come from you. The royal line is included in the promise. Israel will eventually have kings — Saul, David, Solomon. The line of David will produce, in the fullness of time, the great King — the one whose kingdom will have no end. Christ, the King of kings, is included in the kings shall come from you of Genesis 17:6.

An everlasting covenant. The Hebrew is berith olam. The covenant is not a temporary arrangement. It will last as long as creation lasts. The Abrahamic covenant of promise — that Abraham would be the father of a multitude, that all the families of the earth would be blessed in him — stands forever. It finds its fulfillment in the new covenant inaugurated by Christ’s blood. The Abrahamic promise and the new covenant are the same promise unfolded across the centuries.

The Sign in the Flesh

Then God said to Abraham, “As for you, you must keep the covenantal requirement I am imposing on you and your descendants after you throughout their generations. This is my requirement that you and your descendants after you must keep: Every male among you must be circumcised. You must circumcise the flesh of your foreskins. This will be a reminder of the covenant between me and you. Throughout your generations every male among you who is eight days old must be circumcised, whether born in your house or bought with money from any foreigner who is not one of your descendants. They must indeed be circumcised, whether born in your house or bought with money. The sign of my covenant will be visible in your flesh as a permanent reminder. Any uncircumcised male who has not been circumcised in the flesh of his foreskin will be cut off from his people—he has failed to carry out my requirement.”

The covenant gets a sign. Circumcision. The cutting away of the foreskin of the male infant on the eighth day after birth.

To modern Western sensibilities, the institution of circumcision can seem strange. Why this particular sign? Why something so intimate, so physical, so seemingly minor? The biblical answer is theologically rich.

First, the sign is in the flesh. The covenant is not merely a spiritual transaction in the heart. It is marked on the body. The LORD takes the people of His covenant in their actual physical existence, not in some abstract spiritual realm. The mark of belonging is bodily. This will be true of all the LORD’s sacramental signs — they are physical, tangible, real-world. Christianity is not a gnostic religion of escape from the body. Christianity is, like the religion of Abraham, a religion of God’s claim on the body.

Second, the sign is placed at the organ of generation. This is no accident. The covenant promise is, at its heart, a promise of seed — a multiplied offspring who will fill the earth, who will become a nation, through whom all peoples will be blessed. The sign of the covenant is placed at the organ from which the seed comes. Every male child, on the eighth day of his life, is marked precisely there. The point is clear: the seed-line is sanctified to the LORD. The reproductive power of the covenant family is dedicated to the LORD’s purposes. Children produced through this family are produced for the LORD’s covenant. The next generation is His.

Third, the sign is placed on the eighth day. In biblical numerology, eight is the number of new beginning — the day after the seven of creation, the first day of the new week, the day of resurrection. The infant who is circumcised on the eighth day is, symbolically, being given a new beginning under the LORD’s covenant. He is being placed within the covenant people before he is able to choose for himself. He is brought into the covenant by the act of his father and the choice of his God, not by his own decision.

Fourth, the sign is for every male in the household, including foreign-born slaves. The covenant is not strictly genealogical. A foreign slave who is bought into the household becomes part of the covenant people through circumcision. The covenant has a porous edge — it includes non-Israelites who join the household of faith. This will be important throughout the Old Testament; converts (gerim) who join Israel are included in the covenant through circumcision. The LORD’s covenant people is, from the very beginning, broader than ethnic Israel.

Fifth, the sign carries a sanction: any uncircumcised male… shall be cut off from his people. The covenant requires response. To refuse the sign is to refuse the covenant. The Hebrew karat — cut off — is the same root as karat berit, to cut a covenant. The one who refuses to be cut into the covenant is himself cut out of the covenant people. The seriousness of the sign is matched by the seriousness of refusing it.

The remainder of Genesis 17 will tell us that Abraham circumcised himself, Ishmael, and every male of his household that very day (verses 23–27). Abraham was ninety-nine. Ishmael was thirteen. The obedience was immediate and total. Abraham did not negotiate the requirement. He did not delay. The same day the LORD spoke, the sign was put in place.

We will come back to circumcision at the end of this session, when we consider how the New Testament reads this practice in light of Christ.

The Promise to Sarah

Then God said to Abraham, “As for your wife, you must no longer call her Sarai; Sarah will be her name. I will bless her and will give you a son through her. I will bless her and she will become a mother of nations. Kings of countries will come from her!”

Now Sarai gets a new name. Sarai means my princess (in some readings); Sarah means princess — a slightly broader title, less personal, more royal. The wife of the man who is now the father of nations is herself the mother of nations. She too will produce kings. The royal promise extends to her as well.

And the LORD makes explicit what has been implicit. I will give you a son by her. The son of the covenant is going to come through Sarah — not through Hagar. Ishmael, born thirteen years ago through the workaround of Sarai’s plan, is not the son of promise. The son of promise will come from the womb the LORD had previously closed. The barren wife will conceive.

Abraham’s response is striking.

Then Abraham bowed down with his face to the ground and laughed as he said to himself, “Can a son be born to a man who is a hundred years old? Can Sarah bear a child at the age of ninety?”

The Hebrew text says he laughed (yitzchaq). The same root from which Isaac’s name will come. Abraham, hearing the explicit promise that his ninety-year-old wife will bear a son, falls on his face — a gesture of worship — and laughs.

Is this the laughter of unbelief? It is hard to read it any other way. He has just been told something that seems biologically impossible, and his immediate reaction is to laugh and ask whether such a thing could be. He thinks to himself: Shall a child be born to a man who is a hundred years old? Shall Sarah, who is ninety years old, bear a child? The questions are not the questions of a man receiving the promise with confident faith. They are the questions of a man astonished — perhaps amused — at the absurdity of what the LORD is saying.

And then Abraham, perhaps trying to redirect the conversation toward a more plausible outcome, makes a request.

Abraham said to God, “O that Ishmael might live before you!”

This is the patriarch’s preferred solution. He already has a son. Ishmael is thirteen years old, the visible product of his loins, the living son in his household. Why does the LORD need to produce a second son through impossible biological means? Oh that Ishmael might live before you! Make Ishmael the son of the covenant. The promise can be fulfilled through the son who is already here.

The request is moving. Abraham loves Ishmael. He is not ready to set Ishmael aside in favor of a son who does not yet exist. He is offering the LORD what he has, hoping it will be enough.

But the LORD answers with a clear no.

God said, “No, Sarah your wife is going to bear you a son, and you will name him Isaac. I will confirm my covenant with him as a perpetual covenant for his descendants after him. As for Ishmael, I have heard you. I will indeed bless him, make him fruitful, and give him a multitude of descendants. He will become the father of twelve princes; I will make him into a great nation. But I will establish my covenant with Isaac, whom Sarah will bear to you at this set time next year.”

Isaac. The name is the noun form of the verb to laugh — Yitzchaq, “he laughs.” The son of the promise will be named Laughter. The name will memorialize the moment of Abraham’s incredulous laugh. Every time the family says the child’s name, they will recall the moment when the patriarch laughed at the promise of him. The LORD takes the laughter of unbelief and turns it into the name of the son who proves the LORD true. The unbelief is transmuted into testimony.

And the LORD does not refuse Ishmael’s blessing. As for Ishmael, I have heard you; behold, I have blessed him. The LORD has heard Abraham’s request. Ishmael will be blessed. He will be fruitful. He will father twelve princes — twelve, the same covenantal number Israel will eventually have in its twelve tribes. He will become a great nation. But he will not be the son of the covenant of promise. The covenant is with Isaac. Ishmael’s blessing is real, generous, abundant — but it is a parallel blessing, not the seed-line blessing.

Whom Sarah shall bear to you at this time next year. The timing is given. By next year at this time, Sarah will have borne a son. The promise that has waited for twenty-five years is now given a definite date. The wait is almost over.

The chapter then closes (verses 22–27) with Abraham circumcising himself, Ishmael, and every male of his household that very day. The patriarch does not delay his obedience. The sign of the covenant goes into the flesh.

Three Men at Mamre

The LORD appeared to Abraham by the oaks of Mamre while he was sitting at the entrance to his tent during the hottest time of the day. Abraham looked up and saw three men standing across from him. When he saw them he ran from the entrance of the tent to meet them and bowed low to the ground. He said, “My lord, if I have found favor in your sight, do not pass by and leave your servant. Let a little water be brought so that you may all wash your feet and rest under the tree. And let me get a bit of food so that you may refresh yourselves since you have passed by your servant’s home. After that you may be on your way.” “All right,” they replied, “you may do as you say.” So Abraham hurried into the tent and said to Sarah, “Quick! Take three measures of fine flour, knead it, and make bread.”

Genesis 18 opens with a remarkable scene. The LORD appears to Abraham — and appears in human form, as three men, in the heat of the day, by the oaks of Mamre. Abraham is sitting at his tent door. He looks up and sees three travelers approaching.

The text identifies them ambiguously. The narrator says the LORD appeared, but Abraham sees three men. As the chapter unfolds, it becomes clear that one of the three is the LORD Himself; the other two will turn out to be angels who go on to Sodom (Genesis 19:1). The Christian tradition has, since the earliest centuries, wondered about this passage. Some Christian readers have seen the three figures as a foreshadowing of the Trinity — Father, Son, and Spirit. Other Christian readers have seen the central figure as the pre-incarnate Christ, accompanied by two angelic messengers. The Lutheran tradition has not insisted on one reading over another. What is clear is this: the LORD Himself is present, in some visible and intelligible form, in this encounter with Abraham.

Abraham’s response is extravagant hospitality. He runs to meet the visitors. He bows to the ground. He offers water for their feet. He promises a morsel of bread — and then proceeds to prepare a feast. He instructs Sarah to bake bread from three measures of fine flour (a substantial quantity). He runs to the herd, selects a tender young calf, and gives it to a servant to prepare. He fetches curds and milk. He stands by the visitors under a tree while they eat.

The author of Hebrews will eventually highlight this scene. Do not neglect to show hospitality to strangers, for thereby some have entertained angels unawares (Hebrews 13:2). Abraham, in receiving these three visitors at Mamre, was hosting the LORD Himself. The hospitality of the patriarch to the wayfaring stranger turns out to be the reception of God in the flesh — a foreshadowing, perhaps, of the deeper truth that when we receive the stranger, the hungry, the marginal, we are receiving Christ (Matthew 25:35–40).

Then they asked him, “Where is Sarah your wife?” He replied, “There, in the tent.” One of them said, “I will surely return to you when the season comes round again, and your wife Sarah will have a son!” (Now Sarah was listening at the entrance to the tent, not far behind him.

The promise is renewed — this time in Sarah’s hearing. About this time next year, Sarah your wife shall have a son. The promise that was given to Abraham in Genesis 17 is now spoken aloud in Sarah’s house, in language Sarah can hear. The text notes that Sarah is listening from the tent door, just behind Abraham. She hears the announcement.

And Sarah laughs. The same word as Abraham’s earlier laugh — tsachaq. Sarah laughs to herself, internally, and asks the same kind of question Abraham had asked: After I am worn out, and my lord is old, shall I have pleasure? The implausibility is not lost on her. Her body has long since stopped its monthly cycle. She is ninety. The act of conceiving is no longer a possibility for her. She laughs.

And the LORD calls her out on it.

The LORD said to Abraham, “Why did Sarah laugh and say, ‘Will I really have a child when I am old?’ Is anything impossible for the LORD? I will return to you when the season comes round again and Sarah will have a son.” Then Sarah lied, saying, “I did not laugh,” because she was afraid. But the LORD said, “No! You did laugh.”

The LORD heard the laughter that Sarah laughed to herself. This in itself is theologically remarkable. There is no privacy from the LORD. The laughter that Sarah did not say aloud, the laughter that took place only inside her own heart, was heard by the LORD. The LORD knows the secrets of our hearts. The unspoken reactions, the silent doubts, the private incredulity — all of it is open before Him.

Is anything too hard for the LORD? The question is the chapter’s gospel question. The Hebrew is hayippale me-YHWH davar — is any word/thing impossible for the LORD? The question is rhetorical. The answer is no. The LORD’s power is not constrained by Sarah’s biology, by Abraham’s age, by the natural impossibility of what He has promised. El Shaddai — the Almighty — has spoken. The promise will be kept.

This question will echo in the Bible. The angel Gabriel will eventually say the same thing to Mary at the annunciation: For nothing will be impossible with God (Luke 1:37). The same words, in Greek translation of the Septuagint, hover in the background of the angelic announcement of the virgin birth. The pattern that begins with Sarah at the tent door reaches its consummation with Mary at Nazareth. The God who opened the closed womb of the elderly Sarah, in the fullness of time, caused the virgin Mary to conceive without a human father — the deeper miracle to which the pattern of the barren matriarchs was pointing. Is anything too hard for the LORD? The history of redemption is the history of the LORD’s no to that question — He overcomes every barrier, every impossibility, every closed womb, every closed grave, in keeping His promise of the seed of the woman.

Sarah denied it, saying, “I did not laugh,” for she was afraid. Sarah lies. She is afraid of having been caught in unbelief. The pattern of the patriarchs continues — they fall, they hide, they cover. He said, “No, but you did laugh.” The LORD does not let her deny what she did. He names her laughter. He does not condemn her for it. But He does not let her pretend she had not laughed.

The visitors then prepare to leave. They look toward Sodom.

Shall Not the Judge of All the Earth Do Right?

Then Sarah lied, saying, “I did not laugh,” because she was afraid. But the LORD said, “No! You did laugh.” When the men got up to leave, they looked out over Sodom. (Now Abraham was walking with them to see them on their way.) Then the LORD said, “Should I hide from Abraham what I am about to do? After all, Abraham will surely become a great and powerful nation, and all the nations on the earth may receive blessing through him. I have chosen him so that he may command his children and his household after him to keep the way of the LORD by doing what is right and just. Then the LORD will give to Abraham what he promised him.” So the LORD said, “The outcry against Sodom and Gomorrah is so great and their sin so blatant

The visitors prepare to descend toward Sodom. Abraham walks with them to set them on their way. As they walk, the LORD makes an extraordinary statement. Shall I hide from Abraham what I am about to do?

This is the language of friendship. The LORD does not consider Himself bound to act in secrecy. He has chosen Abraham, and Abraham is now His. The relationship has reached the point where the LORD shares with Abraham what He is about to do. Abraham will be called the friend of God in Isaiah 41:8, 2 Chronicles 20:7, and James 2:23. Friend of God, James will eventually say in James 2:23. The patriarch has been brought into a circle of intimacy with the LORD that is rare in Scripture. The LORD will not act on Sodom without first telling Abraham what He is about to do.

And the LORD gives a reason for this confidence in Abraham. I have chosen him, that he may command his children and his household after him to keep the way of the LORD by doing righteousness and justice. The LORD has placed in Abraham the kind of father who will pass on the faith. The covenant will be transmitted through the household; the next generation will know the way of the LORD because the father will teach it. This is the foundation of catechesis in the covenant family — the parents are the primary teachers of the faith to their children. Luther’s Small Catechism is built on exactly this assumption. The household of faith is the school of faith.

So the LORD said, “The outcry against Sodom and Gomorrah is so great and their sin so blatant that I must go down and see if they are as wicked as the outcry suggests. If not, I want to know.”

The LORD names the situation. The outcry against Sodom is great. Their sin is very grave. The LORD is about to investigate and to act.

The Hebrew word outcry (ze’aqah) is significant. It is the same word that will be used in Exodus 2:23 of the cry of Israel under Egyptian slavery — a cry that the LORD heard and responded to with the deliverance of the exodus. The cry from Sodom is the cry of the oppressed, the cry of those abused by the city’s wickedness. The LORD hears that cry. He does not ignore it. Sodom’s wickedness has produced victims, and the victims’ cry has reached the LORD.

The two men turned and headed toward Sodom, but Abraham was still standing before the LORD. Abraham approached and said, “Will you really sweep away the godly along with the wicked? What if there are fifty godly people in the city? Will you really wipe it out and not spare the place for the sake of the fifty godly people who are in it? Far be it from you to do such a thing—to kill the godly with the wicked, treating the godly and the wicked alike! Far be it from you! Will not the judge of the whole earth do what is right?”

The intercession begins. The other two visitors turn toward Sodom. The LORD remains with Abraham. And Abraham, the patriarch, the bearer of the promise, presses the LORD on a matter of justice.

Will you indeed sweep away the righteous with the wicked? The question is theological. If there are righteous people in Sodom, will they be destroyed along with the wicked? Abraham assumes — rightly — that the LORD’s character cannot tolerate such an outcome. Far be it from you… shall not the Judge of all the earth do what is just? The patriarch holds the LORD to the LORD’s own character. The God of justice cannot, by definition, do an unjust thing.

This is a remarkable moment of theological courage. Abraham is not afraid to argue with the LORD. He has been brought into the friendship of the LORD; he is allowed to press the LORD on the LORD’s own character. This is the kind of intercession that will later be modeled by Moses (Exodus 32) and by the prophets. The covenant relationship gives the believer freedom to come boldly before the LORD with questions about justice.

The LORD responds.

So the LORD replied, “If I find in the city of Sodom fifty godly people, I will spare the whole place for their sake.”

The LORD agrees. Fifty righteous in Sodom would be enough to spare the city. Abraham presses further.

Then Abraham asked, “Since I have undertaken to speak to the Lord (although I am but dust and ashes), what if there are five less than the fifty godly people? Will you destroy the whole city because five are lacking?” He replied, “I will not destroy it if I find forty-five there.” Abraham spoke to him again, “What if forty are found there?” He replied, “I will not do it for the sake of the forty.” Then Abraham said, “May the Lord not be angry so that I may speak! What if thirty are found there?” He replied, “I will not do it if I find thirty there.” Abraham said, “Since I have undertaken to speak to the Lord, what if only twenty are found there?” He replied, “I will not destroy it for the sake of the twenty.” Finally Abraham said, “May the Lord not be angry so that I may speak just once more. What if ten are found there?” He replied, “I will not destroy it for the sake of the ten.” The LORD went on his way when he had finished speaking to Abraham. Then Abraham returned home.

The bargaining proceeds in steps. Fifty. Forty-five. Forty. Thirty. Twenty. Ten. Each step, Abraham presses; each step, the LORD agrees. The LORD is patient with Abraham’s repeated lowering of the number. The intercession is not refused. The patriarch is allowed to advocate for the city.

Why does Abraham stop at ten? The text does not say. Perhaps he believes ten is the minimum threshold below which a city cannot really be said to contain righteous people. Perhaps he is afraid to press further. Perhaps he believes Lot’s household — Lot, his wife, his daughters, and perhaps a few others — could constitute a quorum of ten. Whatever his reasoning, Abraham stops at ten. The LORD goes on His way. Abraham returns to his place.

The chapter ends with the question hanging. Are there ten righteous in Sodom? The reader knows the answer is coming — but the reader will learn it in the next chapter. Sodom does not have ten. The intercession, in the end, will not save the city. But the intercession itself is not in vain. The LORD has shown that He will go to extraordinary lengths to spare the city if there are righteous in it. He will not sweep away the just with the wicked. His judgment is measured. His justice is not capricious.

And the figure of Abraham as intercessor — standing before the LORD, pleading for the wicked city, advocating for those who cannot advocate for themselves — points forward to a deeper intercession. The greater Abraham, the true seed of Abraham, will one day stand before the Father and intercede for sinners. He always lives to make intercession for them (Hebrews 7:25), the writer of Hebrews will say of Christ. The patriarch’s bargaining at the oaks of Mamre is a small foreshadowing of the eternal high priestly intercession of Christ before the throne of God for His people.

The Circumcision Made Without Hands

We return now to circumcision — the sign of the covenant given in Genesis 17.

The New Testament will, in due time, reread circumcision in light of Christ. The reading is not that circumcision was somehow misunderstood or wrong; it is that circumcision was a sign that pointed beyond itself to a deeper reality. The Old Testament hints at this. Deuteronomy 10:16 commands Israel: Circumcise therefore the foreskin of your heart, and be no longer stubborn. The LORD, through Moses, was already pointing to the spiritual reality behind the physical sign. The physical circumcision was meant to signify a deeper circumcision — the removal of the rebellious flesh of the heart, the cutting away of stubbornness, the inner sanctification of the believer to the LORD. Jeremiah 4:4 will repeat the call: Circumcise yourselves to the LORD; remove the foreskin of your hearts. The prophets understood that physical circumcision without heart-circumcision was empty. For no one is a Jew who is merely one outwardly, nor is circumcision outward and physical. But a Jew is one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the letter (Romans 2:28–29).

Paul develops this most explicitly in Colossians 2: In him also you were circumcised with a circumcision made without hands, by putting off the body of the flesh, by the circumcision of Christ, having been buried with him in baptism, in which you were also raised with him through faith in the powerful working of God, who raised him from the dead (Colossians 2:11–12).

This is one of the most important New Testament passages on the relationship between circumcision and baptism. Paul says, in effect: the circumcision that you, Colossians, have received is not a physical cutting. It is a circumcision made without hands. It is the circumcision of Christ — the spiritual circumcision that Christ has performed on you. And the means by which this spiritual circumcision was applied to you is baptism. In baptism, the body of the flesh is put off. In baptism, you have been buried with Christ and raised with Him. Baptism, in Paul’s reading, is the circumcision of the new covenant.

The Lutheran tradition has held this connection closely. Luther treats baptism as the New Testament fulfillment of Old Testament circumcision. The Augsburg Confession on Holy Baptism (Article IX) insists that baptism is necessary to salvation and that infants should be baptized — paralleling the Old Testament practice of circumcising infants on the eighth day. Just as Abraham’s son was brought into the covenant of God by an act of the parents on the eighth day after birth, Christian children are brought into the new covenant by baptism, on whatever day is appointed for it. The covenant marker has changed — from circumcision in the flesh to baptism in water — but the pattern of God’s claim on the child from infancy continues.

The differences between circumcision and baptism are real and important. Circumcision was for males only; baptism is for both male and female. Circumcision was a sign of the Abrahamic covenant tied to physical descent (with provision for non-Israelite proselytes); baptism is a sign of the new covenant open to all peoples without ethnic restriction. Circumcision was a cutting that left a mark in the body but did not, of itself, regenerate the heart; baptism, in Lutheran teaching, is a means of grace — a means through which the Holy Spirit works regeneration, forgiveness, and the new birth.

But the continuities are also real and important. Both circumcision and baptism are signs of the covenant — visible, sacramental, given by God’s command. Both are applied to the recipient before the recipient is able to choose — circumcision on the eighth day, baptism normally in infancy in the Lutheran tradition. Both bring the recipient into the covenant people of God — into Abraham’s family in the case of circumcision, into Christ’s church in the case of baptism. Both are gifts received from God, not works performed by the recipient. Both are external marks of an internal reality — the cutting away of the flesh of sin, the dedication of the recipient to the LORD’s covenant purposes.

The pastoral application is enormous. Every baptized Christian shares in the spiritual circumcision that Abraham received in physical form. The Christian who has been baptized has been circumcised with a circumcision made without hands. The body of the flesh has been put off. The dedication to the LORD has been made. The promise that began with Abraham — that all the families of the earth would be blessed in him — has reached the Christian through the same kind of covenant sign that Abraham received, applied now in the new covenant form of baptism. The Christian belongs to the LORD by sacramental gift. The covenant is in the flesh — the flesh that has been buried with Christ in baptism and raised with Him to walk in newness of life.

This is what the New Testament does with Genesis 17. It does not abolish the covenant sign; it deepens it. It does not reject what was done to Abraham; it shows how Abraham’s circumcision pointed to baptism, and baptism points to the deeper circumcision of the heart that the Spirit performs in every believer. The sign that began at the tent of Mamre in the ninety-ninth year of Abraham’s life finds its fullness in the baptismal font of every Christian congregation.

Is anything too hard for the LORD? The chapter’s question echoes here too. The transformation from the patriarchal sign in the flesh to the new covenant sign in water; the inclusion of every nation in the covenant that was once narrowly Abrahamic; the regeneration of the heart by the Spirit applied through water and the Word — none of these are too hard for the LORD. He has done what He promised. The covenant of Abraham has become the covenant of all who believe.

Gathering the Threads

Genesis 17 and Genesis 18 have given us a remarkable session. The covenant has been deepened, given a sign, and given a definite timetable. Sarai has become Sarah; Abram has become Abraham. The promise has narrowed to Isaac specifically. Ishmael has been blessed with a parallel blessing. The sign of circumcision has been placed in the flesh of every male in the household. And then, at the oaks of Mamre, the LORD Himself has appeared with two angelic companions, has eaten Abraham’s hospitality, has confirmed the promise of a son for Sarah within the year, and has admitted Abraham into the council of friendship — disclosing what He is about to do with Sodom and allowing Abraham to intercede.

The session has shown us several important things.

It has shown us the LORD as El Shaddai — the Almighty One who is not constrained by natural impossibility. The God who keeps His promise to barren Sarah is the same God who will keep His promise to virgin Mary, and the same God who will raise His crucified Son from a sealed tomb. Is anything too hard for the LORD? No.

It has shown us the covenant marker in the flesh. The sign that placed the LORD’s claim on Abraham’s household, on his sons, and on all generations of the covenant people. The sign that pointed forward, through the prophetic call for circumcision of the heart, to the baptism of every Christian — the circumcision made without hands, by the circumcision of Christ.

It has shown us the laughter motif. Abraham laughed. Sarah laughed. The son was named Laughter. The LORD took the unbelieving laughter of the elderly couple and turned it into the name of the child who would prove Him true. The laughter of unbelief became the laughter of fulfilled joy when Isaac was born.

It has shown us Abraham as the friend of God. The patriarch who has been brought into the council of the LORD, who is allowed to know what the LORD is about to do, who is allowed to argue with the LORD on a matter of justice. Friend of God, James will eventually call him. The intercession at the oaks of Mamre is a small foreshadowing of the eternal high priestly intercession of Christ.

It has shown us the LORD’s patience with Abraham’s questions. The patriarch presses; the LORD agrees. Fifty becomes forty-five becomes forty becomes thirty becomes twenty becomes ten. The LORD is not impatient with bold prayer. He invites it. He responds to it. The covenant relationship is the basis on which Abraham can speak so freely.

And it has shown us, in the question Shall not the Judge of all the earth do what is just?, the theological anchor for the next chapter. The judgment about to fall on Sodom will be just. The LORD will not sweep away the righteous with the wicked. The terrible destruction of the cities of the plain will be the action of the God who, by His own character, cannot do an unjust thing.

Next session, we turn to Genesis 19. The two angels who continued on toward Sodom will arrive at the city gate. They will be received by Lot. The city will reveal itself in its wickedness. The judgment will fall. Lot and his daughters will escape. Lot’s wife will look back. The Dead Sea will become, in the geography of the land, a permanent monument to what happened to the cities of the plain on the day the LORD destroyed them.

For Discussion

The following questions are for group discussion or personal reflection.

1. The LORD reveals Himself to Abraham as El Shaddai — God Almighty — at the moment when the natural impossibility of the promise has become absolute. What does this name mean for your understanding of God’s power in circumstances that look biologically, financially, or relationally impossible? Where does Scripture press you to trust that nothing is too hard for the LORD?

2. Circumcision was given as the sign of the Abrahamic covenant, placed on every male child on the eighth day after birth, before the child could choose for himself. Paul, in Colossians 2:11–12, identifies baptism as the new-covenant fulfillment of circumcision. How does the continuity between circumcision and baptism shape your understanding of infant baptism? How does the circumcision made without hands press the believer toward what baptism actually does?

3. Both Abraham and Sarah laugh at the promise of a son in their old age. The son is then named Isaac — Laughter. What does it mean that the LORD took their unbelieving laughter and turned it into the name of the son who would prove the promise true? Where in Scripture do you see the LORD’s pattern of turning human doubt into divine testimony?

4. Abraham’s hospitality to the three visitors at Mamre turned out to be his reception of the LORD Himself, accompanied by two angels. Hebrews 13:2 reflects on this: Do not neglect to show hospitality to strangers, for thereby some have entertained angels unawares. How does this episode shape the Christian practice of hospitality?

5. Shall not the Judge of all the earth do what is just? Abraham’s question to the LORD about Sodom presses the LORD on a matter of justice. The LORD does not rebuke the question; He answers it. What does this teach us about the boldness with which the friends of God are permitted to bring questions about justice into His presence?

6. Hebrews 7:25 names Christ as the One who always lives to make intercession for His people — the greater Abraham, the true intercessor at the throne of God. How does this shape your understanding of prayer? What does it mean that, every time you pray, you pray through a Mediator who is right now interceding for you at the right hand of the Father?

Looking Ahead

Session 15 turns to Genesis 19. The two angels who left Mamre with their faces toward Sodom will arrive at the city gate. They will be received by Lot — and the city will reveal itself in the depth of its wickedness. The men of Sodom will demand that Lot hand over his visitors. The angels will strike the men with blindness. Lot will be warned to flee with his family before the destruction falls. The destruction will come — fire and sulfur from the LORD out of heaven. Lot, his wife, and his two daughters will flee. Lot’s wife will look back and become a pillar of salt. The cities of the plain will be utterly destroyed. The Dead Sea will become the permanent geographical witness to what happened on that day.

The chapter is hard reading. It contains the most explicit depiction of human depravity in early Genesis. It contains divine judgment in its most direct form. And it contains, in the last verses, a final dark twist — Lot’s daughters, fearing that no other men remain in the world, will get their father drunk and conceive children by him. The sons born of this incest will become the ancestors of the Moabites and the Ammonites, two peoples who will trouble Israel throughout the Old Testament.

Read Genesis 19 in full before next session. As you read, watch for: the contrast between Abraham’s hospitality at Mamre and the city’s hostility to its guests; Lot’s compromised position as a resident alien in Sodom; the angelic intervention; the LORD’s reluctance to destroy without giving warning; Lot’s hesitation and the angels’ urgency; the wife who looks back; and the difficult final episode in the cave.

Closing Prayer

Lord God Almighty — El Shaddai — who came to Abraham at ninety-nine and to Sarah at ninety and made them parents in their old age — we worship You. You are the God for whom nothing is too hard. You opened the closed womb of Sarah, and in the fullness of time You caused the virgin Mary to conceive without a human father, and You opened the closed tomb of Your own Son. The barriers that look final to us are nothing before You. Thank You for the covenant You established with Abraham, deepened with the sign of circumcision, and consummated in the new covenant of Christ’s blood. Thank You for baptism — the circumcision made without hands — by which we are claimed in the flesh as Your own people. Thank You for receiving us into Your friendship, as You received Abraham at the oaks of Mamre, so that we may speak to You boldly about the things that grieve us. Thank You for the true and greater Abraham, Your Son Jesus Christ, who always lives to make intercession for us at Your right hand. Where we have laughed at Your promise, name our laughter and turn it into joy. Where we have hidden our doubts even from ourselves, draw them into the light and answer them with Your faithfulness. And bring us, with Abraham and Sarah and Isaac and all the company of the redeemed, to the day of fulfillment when every promise will be Yes and Amen, when nothing will be too hard, when the laughter of faith will be the only laughter in Your presence. Through Jesus Christ our Lord, with the Father and the Holy Spirit, one God, world without end. Amen.