1 Corinthians 5:6-8

New Revised Standard Version Catholic Edition

⁶ Your boasting is not a good thing. Do you not know that a little yeast leavens the whole batch of dough? ⁷ Clean out the old yeast so that you may be a new batch, as you really are unleavened. For our paschal lamb, Christ, has been sacrificed. ⁸ Therefore, let us celebrate the festival, not with the old yeast, the yeast of malice and evil, but with the unleavened bread of sincerity and truth.