1 Corinthians 5
Don’t tolerate sex sins
Throw the man out of church1I can’t believe what I’ve heard. It’s this: you’re condoning a case of sexual immorality so depraved that even godless people wouldn’t tolerate it. A man is living in sin with his own father’s wife.  2Look at what your arrogance has done to you. Shouldn’t you be crying about this and asking the man to leave?
3I know I’m not there with you physically. But I’m there in spirit. So listen up. I want you to know I’ve already passed judgment on this man—as effectively as if I had been there in person. 4When you get together, you do that in the name of our leader Jesus.  I am with you in spirit, too. So is the full authority and power of our leader Jesus.  5Show this man the door to his destruction. Do that by kicking him out into the world Satan rules. Maybe this spiritual shock therapy will somehow end up saving him on Judgment Day. 
What’s with all the bragging?6The bragging you’re doing is not a good thing. Don’t you know that even a tiny piece of yeast eventually works its way through the entire lump of dough? 7You’ve got to get rid of that speck of old yeast. You need to be a fresh batch of dough, unaffected by any yeast. Remember that the Messiah, our Passover lamb, was sacrificed. 
8So let’s get rid of that old yeast and celebrate the festival. We don’t need that kind of yeast, loaded with all sorts of evil and wickedness. We celebrate our festival with the yeast-free bread of sincerity and truth.
Avoid so-called believers who blatantly sin9In an earlier letter, I told you not to associate with people who engage in sex sins. 10I wasn’t talking about all sinners in the world, such as folks who are sexually immoral, greedy moneygrubbers, dishonest con artists, or idol worshipers. If I told you to stay away from them, you’d have to leave this world.
11I want to clarify now that the sinful people I’m talking about are those who say they’re your spiritual brothers and sisters. Do not associate with anyone who claims to be a fellow believer, but who is sexually immoral, greedy, an idol worshiper, verbally abusive, a drunk, or a con artist. Don’t you dare even sit down and eat a meal with someone like that. 12What business do I have judging someone outside our community of faith? Isn’t it those who claim to be insiders that we need to judge? 13God will judge the outsiders. “Get rid of the evil person in your group.” 
Most Bible experts say that the man is sexually involved with his stepmother. Scholars speculate that Paul phrased it the way he did to highlight a well-known Jewish law: “Do not have sexual relations with your father’s wife” (Leviticus:18:8 New International Version).
Some Bible experts say that Paul’s implication here is that the incestuous man is essentially committing his sin in the name of Jesus because he is allowed to remain with full privileges in the group that meets in the name of Jesus.
Paul seems to be saying that the believers in Corinth have the authority of both Paul and Jesus to take action against this man.
Scholars churn up intense debates over each phrase in this verse. Most seem to agree that Paul’s main concern is for the spiritual integrity of the Christians in Corinth. They also say Paul shows concern for the sinful man, as well—though to a much less degree than for the community of faith.
Paul linked yeast to Passover to remind people that Jews cleared their homes of yeast during the Passover Festival, and they ate only crackerlike unleavened bread during the Passover meal. They do this to commemorate the meal they ate before they escaped from Egyptian slavery in the Exodus. They left in such a hurry that they didn’t have time to let the bread rise (Exodus 12:34).
Paul seems to be paraphrasing Deuteronomy 17:7, which calls for the Jews to stone to death a sinful person.
Paul is telling the Christians in the church at Corinth to essentially excommunicate one of their members who is engaging in incest, sleeping with what appears to be his stepmother, “his own father’s wife” (5:1). These days, it’s pretty rare for churches to kick members out. Why do you think that is?
What can you see in Paul when you read what he tells the Christians in Corinth to do about the sinful man in their congregation? “Show this man the door to his destruction. Do that by kicking him out into the world Satan rules. Maybe this spiritual shock therapy will somehow end up saving him on Judgment Day” (5:5).”
Paul was astonished that the church leaders in Corinth were bragging about themselves (5:6) instead of dealing with the elephant in the room—the man who was sleeping with his stepmother. Why do you think a community of faith, then or now, would try to ignore a problem like this?
LIFE APPLICATION. Paul uses an analogy that works well for Jewish people because it refers to yeast that’s removed from homes during the Jewish Passover festival. Jews got rid of all the yeast in their house during Passover because they ate only crackerlike unleavened bread— just as their ancestors did when they escaped from slavery in Egypt, under the leadership of Moses (Exodus 12:8, 15, 17). So Paul makes his argument for getting rid of the sinful man by saying, “Let’s get rid of that old yeast and celebrate the festival” (5:8). He wants the church to celebrate worship with integrity. If we wanted to make a case for getting rid of a blatantly fraudulent church member, how might we do that?