6 Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump?
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:
8 Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth.
Paul starts here and warns us that if we have sin in our church it needs to be removed or else it will spread. He goes on to say get the sin out of the church. The church needs to be cleansed thoroughly and not leave anything that is associated with it. Just as unleavened bread symbolized being free so the church is to be unleavened, since it has been separated from the dominion of sin and death by the perfect Passover Lamb, the Lord Jesus Christ. Last he tells us worship not with the old leaven or sin our in our life but with a continual remembrance of the great sacrifice that Jesus made for us. Sin should not be present in our lives as Christians and we should have no desire to sin in our hearts. We should constantly be sincere with the Lord and truth should be our standard.