6 Your boasting is not good. Don’t you know that a little yeast leavens the whole batch of dough? 7 Get rid of the old yeast, so that you may be a new unleavened batch—as you really are. For Christ, our Passover lamb, has been sacrificed. 8 Therefore let us keep the Festival, not with the old bread leavened with malice and wickedness, but with the unleavened bread of sincerity and truth.—1 Cor. 5:6-8 NIV
​Paul​ continues to emphasize the necessity of having a humble mindset. We must live our lives with humility and the attitude of a servant. Jesus is our example of serving others in our daily lifestyle. The leaven of the Pharisees and Sadducees is their teaching of the necessity to keep the Law. In the Old Testament law, the Jewish people could eat no leavened bread during the Feast of the Passover. They were even required to get all the leaven out of their houses so nothing could be tainted with the leaven. They had to celebrate the Passover each year. This required them to kill a sacrificial lamb each time. But Jesus is our sacrificial Lamb and he was sacrificed once for all sin of all times. He does not need to return to the cross each year. Jesus is the bread of Life and because of this, we are not required to follow the old ways. In fact to do so is to add to the plan of salvation things that God does not require of us The leaven that we need to avoid in our life is pride and the desires of the flesh. We replace those things with the fruit of the Holy Spirit who now lives in us. We are”new creations” in Christ Jesus and He has fulfilled the law for us.
17 “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them.–Matt.5:17 NIV