The key passage of 1 Corinthians 5:7-8 directly links two commands—purging out of “old leaven” and the keeping of the Feast of Unleavened Bread—with two reasons for doing so—that we may be a new lump, and “For Christ, our Passover, was sacrificed for us.” Passover is the foundation upon which the Feast of Unleavened Bread is built. These two observances are closely associated, and understanding this will help us to gain more as we remove the leaven from our homes and lives. This message deals with the leaven that affects congregations, drawing lessons from the book of 1 Corinthians.