1 Corinthians 5:7-8
New International Version
7 Get rid of the old yeast, so that you may be a new unleavened batch—as you really are. For Christ, our Passover lamb, has been sacrificed.(A) 8 Therefore let us keep the Festival, not with the old bread leavened with malice and wickedness, but with the unleavened bread(B) of sincerity and truth.