1 Corinthians 5:6-8

Amplified Bible

⁶ Your boasting [over the supposed spirituality of your church] is not good [indeed, it is vulgar and inappropriate]. ^[a]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]? ^7 [b]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. ⁸ 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.^(A)