It seems that ousting the man from the church is obviously to purge the church (v. 7), and hopefully to motivate the man to renounce his sin and return to God (v. 5).

The way it's supposed to happen is at the hands of the whole church, not just a few. This is not an individual actions, but is meant to be a church-wide experience. The primary purpose of the ousting is disciplinary—to restore the person, not so much to punish him. The point is always to help the man.

What "deliver over to Satan" means is discussed quite a bit, and there are numerous possibilities.

1. Some believe that the delivery to Satan will eventuate in a wasting physical illness suffered by the sinner (Barclay, Dods, Knox, Olshausen, Ridderbos, Simon, Thrall). This just doesn't seem right to me.

2. The destruction of the transgressor’s sinful nature (Farrar, Grosheide, Lenski, Lias, Morgan). This one sounds more like what the text is talking about, except that destroying the man's sinful nature is God's business, not Satan's.

3. Physical death at Satan’s hand (Bultmann, Conzelmann, Gilmour, Hurd, Moule, Niebuhr, Lietzmann). This is awful. I can't imagine this is right.

4. Delivery to the Roman civil magistrates (Grafe). This doesn't sound right, either, but I guess it's a possibility.

5. A secret execution (Klausner). What? Can't be. Where do people come up with this stuff?

6. A self-atoning physical death (Doskocil). This doesn't sound right.

7. Delivery to purgatory (Bohren, Stauffer). I don't even think Purgatory is a biblical idea!

8. Banish from Christian fellowship (N.T. Wright, Robertson, Campbell, Page). Yeah, here it is. This is it. See verse 2. [b]Remove him from the community and back into a deceitful world that doesn't honor God.[/b] By removal from the church, the man would lose his spiritual support structure and the protective hand of God over his life, and the subsequent experiences he would have in life would convince him that he had been involved in terrible sin, and he would turn from it and return to the church in repentance and change.

What does Paul mean when he says “deliver him to Satan”?

Oh, and thanks for the great reply.

Yeast, or leaven, was often a symbol of sin in the Bible, though on a few occasions it was a symbol of the growing kingdom of God (Mt. 13.33). In the Passover, yeast was kept out of the bread as a symbol of purity from sin. So let's break down the text.

V. 7: Jesus, the true Passover lamb, has been sacrificed as a true atonement for sin. We celebrate that not by freedom that lets us sin however and as much as we want, but instead by moral standards of righteousness and godliness. The Christian church should be different from what it's like int he world. The "old yeast" is the sin that is infecting the whole church. Paul wants the contamination removed. Get the evil out of that person. And If they can't separate the evil from that person, then they should expel the person.

v. 8: The Festival of Unleavened Bread followed the Passover. The Jews continued to eat unleavened bread for 7 days as an exercise of their purity. Paul is speaking figuratively: They are to let their whole lives be consecrated to God. Be done with the kinds of sins that are characteristic of people without Christ. Don't let sin grow in the fellowship of believers under the guise of liberty. Instead, be people of purity and truth.

I'm willing to talk more, as you wish.

What does it mean in 1 Corinthians 5 to “keep the feast” not with the old leaven?

The context is Paul addressing a sexually perverse believer in the church who needs to be removed.

[quote]“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. 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 ‭5:7-8‬ ‭NKJV‬‬[/quote]

What is the old leaven and what is the leaven of malice and wickedness?