I Corinthians 5:7 Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us.
Leaven was a thin dough made out of wheat flour and water. It was used in the Bible lands to save the housewife the daily task of grinding wheat. It was set out for several days in a crock to ferment before it would be used to leaven bread. The leaven would then be placed in the center of the bread. From inside the leaven's rising properties would take effect throughout the entire "lump" or loaf of bread. Only a small amount of leaven was needed to aid in the rising of the bread, make it flavorful, and give it a light textrue. During the Passover & Feast of Unleavened Bread fresh round flat loaves of bread were made and eaten without the use of leaven. Jesus Christ, our passover, was sacrificed for us. We are to get rid of the old leaven of the world and focus our lives on the Christ within. We are to be new "lumps", fresh, unleavened by the world living according to the abundance of the gift of holy spirit within.