Therefore purge out the old leaven, that you may be a new lump, since you truly are unleavened. For indeed Christ, our Passover, was sacrificed for us. —1 Corinthians 5:7
When leaven is added to bread, gases are released due to fermentation. It is a rotting process. In this way, the bread rises. Just a little bit of leaven can permeate through an entire lump of dough.
Sin is like that too. A little tolerated sin in the church can work its way through the whole body. And it is in this context that Paul addresses the Corinthian church. They had tolerated evil within their fellowship—sin which needed to be purged.
Just a little tolerated sin can permeate through the whole body, rotting it away from the inside out.
In the final plague in Egypt, God made provision for His own people. Every household protected by the blood of the sacrificial lamb escaped the plague. But in every household without the protection of the blood, the firstborn was found dead by morning.
In the same way, God has made provision for the forgiveness of our sins so that we don't have to die as the result of them. That provision is in Jesus Christ, our sacrificial Lamb. Through the shedding of His blood, we can have our sins forgiven.
Paul declared that "Christ is our Passover." It was no accident that Jesus was crucified on the day of Passover. God's Lamb fulfilled the foreshadowing of Israel's Passover, purging the sin that defiled our lives, and providing escape from an otherwise inescapable death.
Father, thank You that You sent Your Son to be our Passover. We receive now the cleansing that He offers. We receive the forgiveness of our sins. In Jesus' name, amen.