1 Corinthians 5:6-8

5:6 Your boasting is not good. Don’t you know that a little yeast ¹  affects ²  the whole batch of dough? 5:7 Clean out the old yeast so that you may be a new batch of dough – you are, in fact, without yeast. For Christ, our Passover lamb, has been sacrificed. 5:8 So then, let us celebrate the festival, not with the old yeast, the yeast of vice and evil, but with the bread without yeast, the bread of sincerity and truth. ³ 

[5:6]  ¹ sn In this passage (5:6-8) yeast represents the presence of evil within the church, specifically the immoral person described in 5:1-5 and mentioned again in 5:13.

[5:6]  ² tn Grk “a little yeast leavens.”

[5:8]  ³ tn Grk “with the unleavened bread of sincerity and truth.”