let us keep the bread of sincerity and truth

1 Corinthians 5:1-13
Paul asked the sexual immorality, greedy, an idolater or a slanderer, a drunkard or a swindler among church should not associate with them. With such a man do not even eat.
But Paul said that is not at all meaning the people of this world who are doing immorality. What business is it of mine to judge those outside the church? God will judge those outside. "Expel the wicked man from among you."
When you are assembled in the name of our Lord Jesus and I am with you in spirit, and the power of our Lord Jesus is present, hand over this man over to Satan, so that the sinful nature may be destroyed and his spirit saved on the day of the Lord.
Boasting is not good. Get rid of the old yeast that you may be a new batch without yeast- as you really are. For Christ, our Passover lamb, has been sacrificed. Therefore let us keep the Festival, not with the old yeast, the yeast of malice and wickedness, but the bread of sincerity and truth. Yeast is means the malice and wickedness.
Why?
Those Christians have brought their old values with them into the church, and never given them up. So the whole church is endangered.
Hand over to Satan: Short-term discipline is to be exercised for the long-term good of both the church and the individual concerned. The man is to be expelled from the church:'delivered over into that region where Satan holds sway'. It is hard to see how this would result in the 'flesh' or 'body' being destroyed.
Leaven: Yeast. often used as a picture of the corrupting power of evil. Bread for the Passover was made without leaven, as a reminder of the Israelite hasty departure from Egypt. Christ has become our Passover sacrifice; it is time we got rid of the old yeast of evil in our lives.
How?
Get rid of all of our old yeast- malice an wickedness.  Bread for the Passover was made without yeast for us, let keep the bread of sincerity and truth.