6 Your boasting is not good. Do you not know that a little leaven leavens the whole lump? 7Cleanse out the old leaven that you may be a new lump, as you really are unleavened. For Christ, our Passover lamb, has been sacrificed. 8Let us therefore celebrate the festival, not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth. – 1 Corinthians 5:6-8
This is the original spring cleaning. Every year in preparation for the celebration of Passover, Jewish families go through their entire house to clean all the leaven (literally) from their dwelling place. For an entire week, there is no leaven to be found and none is allowed. Paul takes this picture as a way of helping us to see our new life in Christ. Christ has come and removed sin; He has cleansed us. Today is the beginning of Passover. Make it a day to clean out the old leaven from your house.