1 Corinthians 5:1-8

It is actually reported [everywhere] that there is sexual immorality among you, a kind of immorality that is condemned even among the [unbelieving] Gentiles: that someone has [an intimate relationship with] his father’s wife. [Deut 22:30; 27:20] And you are proud and arrogant! You should have mourned in shame so that the man who has done this [disgraceful] thing would be removed from your fellowship! For I, though absent [from you] in body but present in spirit, have already passed judgment on him who has committed this [act], as if I were present. In the name of our Lord Jesus, when you are assembled, and I am with you in spirit, with the power of our Lord Jesus, you are to hand over this man to Satan for the destruction of his body, so that his spirit may be saved in the day of the Lord Jesus. Your boasting [over the supposed spirituality of your church] is not good [indeed, it is vulgar and inappropriate]. Do you not know that [just] a little leaven ferments the whole batch [of dough, just as a little sin corrupts a person or an entire church]? Clean out the old leaven so that you may be a new batch, just as you are, still unleavened. For Christ our Passover Lamb has been sacrificed. Therefore, let us celebrate the feast, not with old leaven, nor with leaven of vice and malice and wickedness, but with the unleavened bread of sincerity and [untainted] truth. [Ex 12:19; 13:7; Deut 16:3]