“Your boasting is not good. Do you not know that a little leaven leavens the whole lump? Cleanse out the old leaven that you may be a new lump, as you really are unleavened. For Christ, our Passover lamb, has been sacrificed. Let us therefore celebrate the festival, not with the old leaven… but with the unleavened bread of sincerity and truth.”
— 1 Corinthians 5:6-8
Context & Key Themes
Chapter five begins a new section of the letter. Having spent chapters one through four addressing the factional divisions reported by Chloe’s household, Paul now turns to a specific moral crisis in the Corinthian church that the congregation has apparently decided to tolerate. The chapter addresses a single case of egregious sexual immorality — a man in the church living with his father’s wife — and uses that case to teach the whole church how to handle unrepentant sin within its body. The issue is not only the sin itself, shocking as it is, but the church’s posture toward it. The Corinthians were proud. They should have been grieving.
The chapter also contains one of Paul’s most important clarifications about how Christians are to relate to the surrounding culture versus how they are to relate to people inside the church claiming the name of Christ. Paul had apparently written an earlier letter telling the Corinthians not to associate with sexually immoral people, and they had misunderstood him to mean outsiders. He now corrects the misreading explicitly. The moral boundaries Paul is drawing are not meant to be applied to unbelievers, who live by their own lights and will be judged by God, but to believers whose unrepentant lives would corrupt the church from within.
Summary
Paul opens with report. It is actually reported that there is sexual immorality among you, and of a kind that is not tolerated even among pagans — a man has his father’s wife. The reference is almost certainly to the man’s stepmother, and the relationship appears to be ongoing rather than a single incident. Even Roman law, with its relatively loose sexual mores, prohibited this specific relationship. The Corinthian church knew this, and yet the congregation was not mourning the situation. They were arrogant. Paul demands the ordinary response instead — that the one who had done this be removed from among them.
Paul then describes what he has already done from a distance. Though absent in body, he is present in spirit, and as one present he has already pronounced judgment on the man who did this. When the Corinthians are assembled, and Paul’s spirit is present, with the power of the Lord Jesus, they are to deliver this man to Satan for the destruction of the flesh, so that his spirit may be saved in the day of the Lord. The phrase is difficult, but the shape is clear: removal from the protective covering of the church returns the man to the exposed territory of the world, in hope that the suffering this produces will drive him to repentance and save him in the end. The discipline is redemptive in intent, not punitive.
Paul then explains the principle using Passover imagery. Your boasting is not good. Do you not know that a little leaven leavens the whole lump? Cleanse out the old leaven that you may be a new lump, as you really are unleavened. For Christ, our Passover lamb, has been sacrificed. Let us therefore celebrate the festival, not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth. The Passover reference is doing deep theological work. The church’s identity as redeemed people is tied to a sacrifice already accomplished — Christ, the Passover lamb. The kind of life that corresponds to that redemption is marked by the removal of what the old celebration removed: leaven, the symbol of corruption spreading silently through a whole batch. Tolerating unrepentant sin in the body of Christ is like keeping leavened bread in the house during Passover. The two do not belong together.
The chapter closes with the crucial clarification. Paul had written to them in his earlier letter not to associate with sexually immoral people — not at all meaning the sexually immoral of this world, or the greedy and swindlers, or idolaters, since then they would need to go out of the world altogether. What Paul actually wrote was this: not to associate with anyone who bears the name of brother if he is sexually immoral or greedy, an idolater, reviler, drunkard, or swindler — with such a one not even to eat. For what has Paul to do with judging outsiders? Is it not those inside the church whom you are to judge? God judges those outside. Purge the evil person from among you. The chapter ends on that command, drawn from Deuteronomy.
Reflection
The distinction Paul draws in the chapter’s final section has been misunderstood in both directions throughout church history, so it is worth spelling out clearly. Paul is not telling Christians to withdraw from the world or to avoid all contact with people whose lives do not match Christian ethics. He explicitly says the opposite — such avoidance would require leaving the world entirely. What he is telling Christians to do is maintain the church’s internal integrity by refusing to extend the church’s fellowship to members whose unrepentant lives contradict what they claim. The outside gets the gospel and ordinary human contact. The inside gets the standards that belonging to Christ actually entails.
The Corinthians’ specific failure was arrogance. Paul does not say they were unaware of the man’s behavior. He says they were puffed up — the same word that has been echoing since chapter four. Their arrogance apparently extended to treating the situation as evidence of their advanced spiritual freedom, as if tolerating what even pagans rejected demonstrated how far beyond conventional morality they had progressed. Paul’s response destroys that framing. The behavior in question was not a marker of freedom; it was corruption spreading silently through the lump, and the congregation’s posture toward it was not sophistication but negligence.
The redemptive intent of the discipline is easy to miss and important to name. Paul is not writing off the offending man. The point of removal is his salvation — that his spirit may be saved in the day of the Lord. Exposure to the consequences of sin outside the protective context of the church is meant to produce repentance. The same pattern will emerge in 2 Corinthians, where it appears the discipline worked and Paul writes to urge the church to forgive and restore the man lest he be overwhelmed by excessive sorrow. Church discipline in the Pauline sense is never final punishment; it is intervention intended to rescue. When it is not aimed at rescue, it has become something other than what Paul describes.
And the Passover image deserves one more glance. The church’s holiness is not a moralistic demand but a response to an accomplished sacrifice. Christ, our Passover lamb, has been sacrificed. The believing community is already unleavened in status; the command to cleanse out the old leaven is a command to live out what is already true. This is the pattern that runs through Paul’s ethics everywhere — become what you already are. The chapter is not asking the Corinthians to earn holiness by disciplining sin. It is asking them to stop living inconsistently with holiness Christ has already secured.