1 Corinthians 5:7-8

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. (NRSV)

7 Clean out the old leaven so that you can be a fresh batch of dough, because unleavened is what you are supposed to be.  The Anointed, our “Passover lamb,” 8 so that we would celebrate the feast of our liberation not with the old leaven of vice and base behavior, but with the unleavened bread of integrity and truth. (SV)