πλανάω

The English word planet comes from a surprising place. It does not come from a Latin scientific term coined by Renaissance astronomers. It does not come from a modern technical vocabulary developed for the heliocentric model. It comes from Greek — specifically from planētēs (πλανήτης), which means wanderer.

The ancient Greek astronomers had noticed that most of the stars in the night sky stayed in fixed positions relative to each other, rotating together as the celestial sphere turned. But seven of those bright objects did not stay fixed. They moved through the constellations in their own paths, sometimes traveling forward, sometimes appearing to retreat, sometimes pausing in their motion. The Greeks called these seven the planētai — the wanderers. We know them today as Mercury, Venus, Mars, Jupiter, Saturn, the Sun, and the Moon. (The ancient Greek list included the Sun and Moon because they too moved against the fixed stars.) The word for planet in English preserves the Greek word for wanderer without alteration.

This is the chapter’s central word: planaō, the verb of wandering, of being led astray, of deceiving and being deceived. The image is spatial. A person walks a path; the person is led off the path; the person wanders. The Greek captures sin’s operation as a wandering, not as a sudden catastrophe but as a continued deviation from the way that should have been followed.

When the New Testament uses planaō, it draws on this whole image-bank. The wandering of stars. The wandering of sheep without a shepherd. The wandering of disciples led astray by false christs. The wandering of an apostate church seduced by deceptive teaching. The wandering of the whole world deceived by the great dragon at the end of the age. All of these uses share the same Greek verb, and the same underlying picture: someone has been led off the right path.

This chapter is about that word — the closing word of Part II’s vocabulary for the fallen world.

The Word

The Greek word is πλανάω (planaō), pronounced in the Erasmian convention as pla-NAH-oh, with the accent on the second syllable. The word is a verb and appears throughout the New Testament in both active and passive forms, with the voice making a significant theological difference.

In the active voice, planaō means “to lead astray,” “to cause to wander,” “to deceive.” The subject of the verb is the agent of deception; the object is the one being deceived. Matthew 24:5 — many will come in Christ’s name “and will lead many astray” (active).

In the passive voice, planaō means “to wander,” “to be led astray,” “to be deceived.” The subject of the verb is the one being deceived; the agent is left implicit or expressed in a prepositional phrase. Hebrews 5:2 — “He is able to deal gently with the ignorant and wayward (planōmenois, passive participle, those who are being led astray).”

The active-passive distinction is theologically important. The New Testament holds both: there are agents of deception who actively lead others astray, and there are persons who are led astray and wander. The same Greek root names both ends of the transaction. Often the two ends meet in the same person — 2 Timothy 3:13 — “evil people and impostors will go on from bad to worse, deceiving and being deceived (planōntes kai planōmenoi).” The deceivers are themselves deceived; the leading-astray is mutually reinforcing.

The word family is moderate in size:

Planē (πλάνη) — error, deception, the state of being led astray. The corresponding noun. Used at Romans 1:27 (the “due penalty for their error”), 2 Thessalonians 2:11 (a “strong delusion”), 1 John 4:6 (the “spirit of error”). The noun names the condition of being deceived, not just the act of deceiving.

Planos (πλάνος) — a deceiver, an impostor (adjective and substantive). Used at Matthew 27:63 (the Pharisees calling Jesus a planos, an impostor), 2 Corinthians 6:8 (Paul described as a planos by his opponents), 1 Timothy 4:1 (the “deceitful spirits” — pneumasin planois). The substantive form names a person who deceives.

Apoplanaō (ἀποπλανάω) — to lead away, to seduce. The compound form with apo- (away from). Used at Mark 13:22 (“to lead astray, if possible, the elect”) and 1 Timothy 6:10 (“through this craving some have wandered away from the faith”). The compound emphasizes the separation from the right path.

Planētēs (πλανήτης) — wanderer, planet. Used at Jude 13 — “wandering stars (asteres planētai), for whom the gloom of utter darkness has been reserved forever.” The noun preserved in English as planet.

The etymology of planaō runs back to an Indo-European root meaning “to wander” or “to roam.” The Greek family is well established by Homer’s time, with the verb used for the wanderings of Odysseus and the meanderings of various mythological figures. By the classical period, planaō could be used metaphorically for moral or intellectual wandering — straying from a teacher’s instruction, deviating from a settled truth, departing from a moral course. The New Testament inherits all of these senses and develops them theologically.

The Septuagint background is significant. Planaō in the LXX translates several Hebrew verbs, most importantly ta’ah (תָּעָה, to wander, to err) and shagah (שָׁגָה, to go astray, to err inadvertently). The Hebrew verbs carry the same wandering image as the Greek, with overlapping moral and spiritual senses. Key Old Testament passages:

Isaiah 53:6 — “All we like sheep have gone astray (Hebrew ta’ah, LXX planaō); we have turned — every one — to his own way; and the LORD has laid on him the iniquity of us all.” One of the most theologically dense Old Testament uses. The wandering is universal (all we like sheep); the wandering is individual (every one to his own way); the wandering is corrected through the substitution of the Servant.

Ezekiel 34:6 — “My sheep wandered (planaō) over all the mountains and on every high hill. My sheep were scattered over all the face of the earth, with none to search or seek for them.” The image of God’s people as wandering sheep without a shepherd. The chapter goes on to promise that God Himself will be the Shepherd (Ezekiel 34:11-16), which the New Testament identifies with Christ (John 10:11).

Jeremiah 23:13 — “In the prophets of Samaria I saw an unsavory thing: they prophesied by Baal and led my people Israel astray (planaō).” False prophets as agents of leading-astray; the people as those being led. The pattern recurs throughout the prophetic literature.

Psalm 119:176 (LXX 118:176) — “I have gone astray (planaō) like a lost sheep; seek your servant, for I do not forget your commandments.” The believer’s confession of wandering combined with the prayer for the shepherd’s seeking.

The wandering-and-being-found pattern of the Old Testament is foundational for the New Testament’s planaō vocabulary. The same image — sheep wandering, shepherd seeking, the one going astray being brought back — runs from Ezekiel 34 to Luke 15 (the parable of the lost sheep) to 1 Peter 2:25 (the believer who has returned to the Shepherd of his soul).

Range of Meaning

Planaō in the New Testament covers a meaningful range:

To wander physically. Less common in the New Testament but present in some usages. Hebrews 11:38 — Old Testament saints “wandering (planōmenoi) about in deserts and mountains, and in dens and caves of the earth.” The physical wandering of the persecuted faithful.

To deceive (active). The most common Pauline and Johannine sense. Someone leads another astray through false teaching or false promise. Matthew 24:4 — “see that no one leads you astray.” 1 Corinthians 6:9 — “Do not be deceived.” James 1:16 — “Do not be deceived, my beloved brothers.”

To be deceived, to wander spiritually (passive). The complementary sense. The person is led astray, often unawares. Galatians 6:7 — “Do not be deceived: God is not mocked.” 2 Timothy 3:13 — “deceiving and being deceived.” The believer can be deceived as well as deceive.

To go astray morally or spiritually. Closely related to the passive sense but with emphasis on the person’s own deviation rather than external agency. 1 Peter 2:25 — “you were straying like sheep.” James 5:19 — “if anyone among you wanders from the truth.”

Deceivers as persons (planoi). The substantive form. False teachers, impostors, leaders-astray as a category of persons. 1 Timothy 4:1 — “deceitful spirits.” 2 John 7 — “many deceivers (planoi) have gone out into the world.”

The cosmic deceiver. The eschatological dimension. Satan as ho planōn (the one who deceives) the whole world. Revelation 12:9 — “the great dragon… the devil and Satan, the deceiver of the whole world.”

Where You’ll Meet It

Matthew 24:4-5, 11, 24. “See that no one leads you astray. For many will come in my name, saying, ‘I am the Christ,’ and they will lead many astray… And many false prophets will arise and lead many astray… For false christs and false prophets will arise and perform great signs and wonders, so as to lead astray, if possible, even the elect.” The Greek verb planaō appears multiple times in Jesus’s Olivet Discourse, always in the active sense — false teachers and false christs as agents of deception.

The passage is one of Christ’s most extended warnings about religious deception. The setting is eschatological — the discourse responds to the disciples’ question about the end of the age — but the warning has continuous application throughout church history. The pattern Christ describes is consistent: false christs claiming His name, false prophets appearing in His authority, signs and wonders impressive enough to deceive nearly everyone. The believer’s task is vigilance — blepete (see, watch) — and the criterion will be developed in the apostolic letters that follow.

The phrase “if possible, even the elect” is theologically loaded. The Greek ei dynaton kai tous eklektous leaves the question open: can the elect be deceived? Some traditions read this as implying that the elect cannot be deceived (the impossibility is real, “if possible” being a hypothetical contrary to fact). Other traditions read this as implying that the elect can be deceived, with the deception threatening even those whom God has chosen. The Lutheran reading has tended toward the cautious middle: the elect are kept by God’s grace, but the threat of deception is real, and complacency about one’s own immunity to deception is itself one of the marks of the deceived.

1 John 4:1-6. “Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world. By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, and every spirit that does not confess Jesus is not from God. This is the spirit of the antichrist, which you heard was coming and now is in the world already… We are from God. Whoever knows God listens to us; whoever is not from God does not listen to us. By this we know the Spirit of truth and the spirit of error (planēs).” The Greek includes the noun planē (error) in the climactic distinction at verse 6.

The passage gives the practical criterion for Christian discernment. Faced with multiple competing religious voices, the believer is to test the spirits — and the test is concrete. The Christological confession of Jesus Christ come in the flesh is the criterion. A spirit (a teacher, a movement, a doctrine) that confesses this is from God. A spirit that does not confess this is not from God; it is the spirit of antichrist; it is the spirit of error.

This criterion has substantial confessional Lutheran weight. The Lutheran tradition has historically held that the test of orthodox teaching is Christological — does the teaching confess Christ rightly, in His full deity and full humanity, in His person and work? Heresies of the early church (Arianism, Docetism, Nestorianism, Monophysitism) were all judged by their Christology. The Reformation’s break with Rome was judged by its handling of the Christological doctrine of justification — does this teaching confess Christ as the sufficient and unique Savior?

The 1 John 4 criterion is not a complete test of orthodoxy (it doesn’t address every doctrinal question), but it is the primary test. Whatever else is at stake, the Christological confession is at the center. Lutheran lay readers can use this criterion as a first-pass filter for evaluating contemporary religious teaching: does this teacher, movement, or doctrine confess Jesus Christ come in the flesh — His true deity, His true humanity, His unique saving work?

2 Timothy 3:13. “But evil people and impostors will go on from bad to worse, deceiving and being deceived.” The Greek: ponēroi de anthrōpoi kai goētes prokopsousin epi to cheiron, planōntes kai planōmenoi. The participial phrase at the end — planōntes kai planōmenoi — captures the chapter’s central insight about how deception works.

Those who deceive are themselves deceived. The agents of false teaching are not merely cynical manipulators (though some may be); they are themselves caught in the deception they propagate. The deception spreads through them because they have first been infected by it. This means that the New Testament’s response to deception is not primarily moral indignation against the deceivers but Christological correction of the doctrine. The deceivers need the truth too. The deception is not just a moral failure of the deceivers; it is a captivity from which they themselves need release.

This emphasis matters pastorally. The Christian community engages false teachers not primarily with denunciation but with the gospel that exposes the deception. The deceivers may eventually be confronted and removed from teaching positions (the apostolic letters do this; the early church councils did this), but the underlying issue is the captivity of the deceivers themselves, and the proper Christian response is the proclamation of the truth that frees.

Revelation 12:9. “And the great dragon was thrown down, that ancient serpent, who is called the devil and Satan, the deceiver of the whole world — he was thrown down to the earth, and his angels were thrown down with him.” The Greek: ho planōn tēn oikoumenēn holēn. The present participle ho planōn — “the one who is deceiving” — is one of Satan’s defining titles in the Apocalypse.

The cosmic dimension of planaō. Satan is not primarily the tempter (though he tempts), not primarily the accuser (though he accuses), not primarily the destroyer (though he destroys); Satan is the deceiver. His central operation in the world is deception — the leading-astray of the nations through false teaching, false religion, false philosophy, false hope. The earth is the territory of his deception; the gospel is the announcement that the deceiver has been thrown down.

The verse links Christ’s victory at the cross (the context of Revelation 12) to the deceiver’s defeat. Satan’s deception is real but bounded. He deceives in this present age, but his defeat is settled in Christ. The final eschatological vision of Revelation 20:10 — Satan thrown into the lake of fire — closes the deception era forever.

1 Peter 2:25. “For you were straying like sheep, but have now returned to the Shepherd and Overseer of your souls.” The Greek: ēte gar hōs probata planōmena, alla epestraphēte nyn epi ton poimena kai episkopon tōn psychōn hymōn. The passive participle planōmena — “being led astray” — names the universal pre-Christian condition.

The verse is a direct echo of Isaiah 53:6 — “all we like sheep have gone astray.” Peter applies the Old Testament confession to his readers’ pre-conversion state: you were the wandering sheep of Isaiah 53; now you have returned to the Shepherd, who is Christ. The return is not the sheep’s achievement; the return is the result of the Shepherd’s seeking work, the laying-of-iniquity that Isaiah 53 promises.

This is the chapter’s pastoral heart. Every Christian’s testimony is the testimony of the returning sheep. The believer was planaō — being led astray, wandering, lost — and has been brought back by the Shepherd’s work. The pattern is universal among Christians, regardless of how dramatic or undramatic the conversion narrative may be. We were all wandering. The Lord laid our iniquity on Christ. We have returned to the Shepherd.