I Corinthians 5

I Corinthians 5:1-2:
It is actually reported that there is sexual immorality among you, and such sexual immorality as is not even named among the Gentiles—that a man has his father’s wife!
2 And you are puffed up, and have not rather mourned, that he who has done this deed might be taken away from among you

“Our security against sin lies in our being shocked at it.”
-- William Barclay

The Corinthian church's coddling of this perversion gave the people of Corinth the appearance that God's people would allow this sin—a sin even unbelievers would never tolerate! Inside the church it gave the appearance that one could continue in sin and still remain part of the body. The apostle warns them that, just as a pinch of leaven will puff up a whole loaf of bread—or as one rotten apple will corrupt a whole barrel of them—so this sin, if allowed to continue, would ruin the entire church. -Bible Tools

I Corinthians 5:3-7:
3 For I indeed, as absent in body but present in spirit, have already judged (as though I were present) him who has so done this deed. 4 In the name of our Lord Jesus Christ, when you are gathered together, along with my spirit, with the power of our Lord Jesus Christ, 5 deliver such a one to Satan for the destruction of the flesh, that his spirit may be saved in the day of the Lord Jesus.
6 Your glorying is not good. Do you not know that a little leaven leavens the whole lump? 7 Therefore purge out the old leaven, that you may be a new lump, since you truly are unleavened. For indeed Christ, our Passover, was sacrificed for us.

The English “actually” is the Greek holōs, a rare form which occurs in I Corinthians several times . It is a form of the term holōs, which means “wholly,” “altogether.” This rare form seems to mean “widely known” (cf. NJB). This may have been one of the reasons Paul was so upset over this flagrant immorality. The Corinthian church was glorying in it and it was being widely reported to the other churches. Paul had to deal with this out-of-bounds action and the attitude of this church lest they negatively affect all churches -Robert Utley

I Corinthians 5:8:
8 Therefore let us keep the feast, not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth.

I Corinthians 5:9-13:
9 I wrote to you in my epistle not to keep company with sexually immoral people.
10 Yet I certainly did not mean with the sexually immoral people of this world, or with the covetous, or extortioners, or idolaters, since then you would need to go out of the world.
11 But now I have written to you not to keep company with anyone named a brother, who is sexually immoral, or covetous, or an idolater, or a reviler, or a drunkard, or an extortioner—not even to eat with such a person.
12 For what have I to do with judging those also who are outside? Do you not judge those who are inside?
13 But those who are outside God judges. Therefore “put away from yourselves the evil person.”

Jack Wellman

When I was witnessing to a stranger the other day, he was convinced that he was a pretty good person, but compared to whom? Compared to his own ideas of what is good and what is bad. God’s idea is that we need to be perfect, having the required righteousness of Christ. I reminded him that none of us are really good, not even one of us (Rom. 3:10); it’s just that we’ve been forgiven by a very good God. He said, “Well, at least I’m not a murderer,” but I told him that each of us will have to stand and give an account for what we’ve done in this life (Rom. 14:12; 1 Cor. 5:10) and that God will not say, “Well, compared to your neighbor there, you’re a pretty good guy.” No, we will stand alone, and God won’t say, “Okay, I’ll wait until you find someone who’s worse than you and then judge you according to how bad they are.” Try that in a court of law. I can guarantee that it won’t work.
Paul said that not only is it foolish to compare ourselves with others, but we dare not even try to classify ourselves in a certain standing before God based upon what we think (2 Cor. 10:12a). Jesus said that we must be perfect as our heavenly Father is perfect (Matt. 5:48) and that our righteousness must exceed that of the Pharisees (Matt. 5:20), so that presents a problem. Nothing sinful or imperfect can even enter heaven (Rev. 21:27). We must compare ourselves to the model of Christ and not others, and that’s a pretty high bar to reach, but there is a solution. For those who have repented and trusted in Christ, they will be seen as having the same righteousness as Christ (2 Cor. 5:21). Problem solved. - Jack Wellman; Rhetorical Jesus; Do You Compare Your Life To People Around You, or to Me? 10.8.23