What does 1 Corinthians 5:12 mean?
Paul has been clear: Christian churches must remove from their community those known to be participating in obvious sin. They should not associate with such people if those people claim to be Christians. The purpose of this is to encourage repentance in the sinner (1 Corinthians 5:5; 2 Thessalonians 3:14–15), protect the spiritual health of the congregation (Jude 1:12; Galatians 2:4; 2 Peter 2:1–2), and avoid giving the world excuses to slander Christ (1 Peter 2:12).He has also been clear that this teaching does not apply to unbelievers. Now Paul asks rhetorically what he has to do with judging those who are outsiders, meaning non-Christians. Even Paul has not been given the responsibility of judging those who have not trusted in Jesus for salvation. He will write in the following verse that God judges unbelievers.
Perhaps this is why Paul never instructs the Corinthians regarding the woman involved in the affair with her husband's son. Based on these verses, she apparently was not a self-identified Christian and wasn't involved in the church at Corinth. If so, they would have no responsibility to hold her accountable for her actions. That doesn't mean they'd have no right to call out sinful behavior (Matthew 28:19–20; Acts 3:11–26), simply that it was not their job to discipline a non-believer.
With another rhetorical question, Paul insists that Christians do have the responsibility to judge those inside the church. In other words, Christians are called by God to hold each other accountable for ongoing participation in obviously sinful actions.
We should note that this practice, called "church discipline," is not often carried out in Christian churches despite this clear teaching. The result is an epidemic of poisonous spiritual influences (Jude 1:12; 2 Peter 2:1; Galatians 2:4) and much criticism from the non-believing world (1 Peter 2:12; 2 Peter 2:2). On the other hand, some of what is called "church discipline" today has been carried out in a manner which is unloving, inconsistent, an unhelpful to the reputation of Christ (Galatians 6:1; Matthew 18:15–20).
Obviously, churches must be prayerful and wise about when and how to apply Paul's instructions in 1 Corinthians 5. The goal is not self-righteousness or vindictive revenge. Rather, it should be protection of truth and the repentance of the sinner.
First Corinthians 5:9–13 introduces Christian teachings on church discipline, conflict resolution, and the power of God to cleanse us from sin. After demanding the church in Corinth excommunicate someone for flagrant sin, Paul reminds them that those who claim to be Christians are to be held to a higher standard. Specifically, the church must not accept the fellowship of those who persist in blatant, stubborn sin. Non-believers, in contrast, aren't subject to that judgment. Paul insists that Christians must not even share a meal with someone who identifies as Christian but refuses to stop participating in sin.
Paul confronts the church in Corinth for failing to respond to a self-identified believer having a sexual affair with his father's wife. He insists they must remove the man from their community—to refuse his participation in the church—referred to here as delivering him to Satan. As the Jewish people would do during Passover, they must remove the leaven of this man and his sin from among them, to prevent it from spreading to the entire church. Christian congregations should not associate with those who claim to be believers, yet flaunt their sin.
