1 Corinthians 5:7
7 Purge out the old leaven that you may be a 1new lump, even as you are unleavened; for our 2aPassover, Christ, also has been sacrificed.
72 This indicates that the apostle considered the believers God's chosen people, who have had their Passover, as typified by the one in Exo. 12. In this Passover, Christ is not only the Passover lamb but also the entire Passover. To be our Passover, He was sacrificed on the cross that we might be redeemed and reconciled to God. Thus, we may enjoy Him as a feast before God. In this feast no leaven is allowed to be present. Sin and the redeeming Christ cannot go together.