συνείδησις

In April of 1521, Martin Luther stood before the Diet of Worms and refused to recant his writings. The substance of his closing statement contained a phrase that has shaped Lutheran piety since: his conscience, he said, was captive to the Word of God. To act against conscience was neither right nor safe. He could not — he would not — recant.

The Greek word for “conscience” in the New Testament is suneidēsis. It is the word behind Luther’s claim at Worms, and it is the word behind Paul’s repeated appeals to a “good conscience” in his letters.

The word does not mean what most modern English speakers mean when they use “conscience.” Most modern English speakers mean something like a feeling of moral discomfort — the inner sense that something is wrong, the gnawing unease after a bad action, the warm assurance of having done right. The New Testament word means something more specific: a faculty of moral knowing, bound to a standard outside itself, that bears witness in the soul. The gap between those two meanings is the subject of this chapter.

The Word

συνείδησις (suneidēsis), pronounced soo-NAY-day-sis. A feminine noun, third declension. The family includes the verb synoida (to know with), the participle syneidōs (knowing-with), and the abstract noun suneidēsis itself.

The etymology is the chapter’s first interpretive clue. Suneidēsis is a compound: sun (συν, “with”) + a noun derived from the verb oida (to know). The literal sense is knowing-with — knowing-with oneself, or perhaps, in some scholarly readings, knowing-with another (typically God). The word names not the act of knowing but the state of having moral knowledge alongside oneself — the way a person carries an internal witness to what he has done and what he is doing.

The word is unusual in the New Testament. It does not appear in the Septuagint at all in the relevant sense. It is a Greek philosophical word that the New Testament writers — especially Paul — picked up from the Hellenistic moral discourse of their day and pressed into specifically Christian service. The Stoics had used it. So had popular ethical writers. Paul takes the term and gives it a shape that orthodox Christianity has held ever since: conscience as the internal moral witness, neither autonomous nor untrustworthy, but always operating in relation to a standard outside itself.

Range of Meaning

In its New Testament usage, suneidēsis covers:

• The moral self-awareness of a person — knowing oneself in moral terms.
• The internal witness that bears testimony about right and wrong.
• The state of moral integrity considered as something that can be intact or damaged — a “good” conscience, a “clear” conscience, a “weak” conscience, a “defiled” conscience, a “seared” conscience.
• The trained or untrained faculty as a particular person possesses it. Conscience is not a uniform thing across all people. It can be informed, malformed, hardened, or healed.

The word does not mean feelings of guilt in the modern sense. A person with a seared conscience can do dreadful things and feel nothing. A person with an oversensitive conscience can feel guilty for matters that are not sins. Suneidēsis names the faculty of moral knowing; the feelings that may or may not accompany its operation are downstream.

Where You’ll Meet It

“For when Gentiles, who do not have the law, by nature do what the law requires, they are a law to themselves, even though they do not have the law. They show that the work of the law is written on their hearts, while their conscience also bears witness, and their conflicting thoughts accuse or even excuse them…” (Romans 2:14–15, ESV)

Paul’s first major use. Even pagans who have not received the Torah have suneidēsis — conscience — that bears witness regarding right and wrong. The natural law (the moral order God has built into creation) operates through conscience even where the Mosaic Law is not known. This is not Paul saying that conscience is sufficient for salvation; it is Paul establishing that all people are accountable, because all people have an internal moral witness, however attenuated.

“I am speaking the truth in Christ — I am not lying; my conscience bears me witness in the Holy Spirit.” (Romans 9:1, ESV)

Paul appeals to his own conscience as a witness to his sincerity. The conscience here is not the Holy Spirit; it is Paul’s own faculty of moral self-awareness, operating “in the Holy Spirit” — that is, under the Spirit’s influence and in line with God’s truth. Worth noting because it distinguishes conscience from the Spirit; they cooperate but are not identical.

“However, not all possess this knowledge. But some, through former association with idols, eat food as really offered to an idol, and their conscience, being weak, is defiled… But take care that this right of yours does not somehow become a stumbling block to the weak.” (1 Corinthians 8:7, 9, ESV)

The chapter on food offered to idols. Paul distinguishes between those whose conscience is weak (trained in ways that make eating such food a sin for them, even if it is not a sin in itself) and those whose conscience is strong (knowing that idols are nothing). The stronger party has the freedom but bears a responsibility: do not exercise your liberty in ways that lead the weaker brother to act against his own conscience. The passage assumes that conscience can be wrong about the matter but is still binding for the person who has it.

“The aim of our charge is love that issues from a pure heart and a good conscience and a sincere faith.” (1 Timothy 1:5, ESV)

Pastoral aim language: the goal of teaching is love that flows from three things together — a pure heart, a good conscience, and a sincere faith. Conscience is one of the three. The “good conscience” here is not the conscience of someone who feels good about himself; it is the conscience of someone whose moral integrity is intact, whose internal witness is not currently accusing him of unrepented sin.

“How much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our conscience from dead works to serve the living God.” (Hebrews 9:14, ESV)

The decisive theological statement. Conscience itself can be purified — not by self-effort, not by moral improvement, not by sincere intention, but by the blood of Christ. The conscience of the Old Testament worshiper, troubled by dead works, is cleansed by the once-for-all sacrifice of Christ. This is what the Christian receives in justification: a conscience cleansed.

“Baptism… now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience, through the resurrection of Jesus Christ…” (1 Peter 3:21, ESV)

Baptism delivers, among its gifts, a good conscience. The phrase Peter uses is suneidēseōs agathēs eperōtēma — literally “the appeal/pledge of a good conscience” — and translators have debated whether it means the appeal for a good conscience or the pledge of a good conscience. Either reading lands in the same theological place: baptism is the place where the Christian’s conscience is given its goodness as gift.