“...after so many thousands of people had gathered together that they were stepping on one another, He began saying to His disciples first of all,"Beware of the leaven of the Pharisees, which is hypocrisy.”"
The Lord warned his twelve against the leaven of the Pharisees. The disciples were concerned about the obvious failings, the practical mistakes they had made that were evident to all. But the Lord spoke about something else, something it took clarification to bring their attention to.
Why tell them to “look out” for it unless there were danger - danger that it would take root in themselves? This is why he calls it “leaven”. It only takes a little, but once it finds its way into the dough, it will grow, and grow, until it has infected the whole.
Look out for it. We see men fall like trees in a forest full of loggers, and we think Oh God, look at the hypocrisy! The leaven has been discovered, once its work was done. Are the disciples of Christ immune? No! We have need to watch. Neither it is a harmless reality of the Kingdom, that hypocrisy is present in some. You might hear it spoken about in some circles when talking about the nature of the Church: “Yes, the church is full of hypocrites, there’s room for one more”. This does not address the leaven with the same wariness that the Lord commands. But what the Lord commands is not just to look out for this leaven in others, but in ourselves. There would be little point in watching if prevention were impossible.
I don’t say this because I’ve seen hypocrisy take root in other men. It is, like leaven, a silent, slow, steady worker. You don’t notice it, but your religion becomes less and less about communion with God and doing his will (concerning yourself with His Kingdom and Righteousness) and more and more becomes “I must do these things, so that people will know there is a godly man on the earth.” And all the while dark things grow in our private practice. Lies and inconsistencies grow when we are not in the light of public opinion and choke the life that once flowed from God to us in private. We say things we ought not say, we look at things we ought not look at, we meditate on things we ought not meditate on, and desires for dark things grow where there was once light. But there is nothing covered up that will not be revealed, and hidden that will not be known.
“Take heed” - Watch out for this! It is always there, the leaven is like pollen in the air, encapsulated in teachings that are mere human traditions, in a prideful attitude that is grateful it is not like other men, excusing its vices (evil thoughts--murder, adultery, sexual immorality, theft, false testimony, slander) while making sure to maintain the clean exterior, convincing themselves that it is for the glory of God that they must maintain appearances. In the Church in Corinth, it manifested among other things as a boastful concern for being of a prestigious party while allowing sexual immorality to flourish in their midst. In Peter it manifested as a refusal to eat with Gentiles.
Watch out, it is in the world still. If you see it growing in you, cut it off and throw it away. Your boasting is not good. Do you not know that a little leaven leavens the whole lump of dough? Clean out the old leaven so that you may be a new lump, just as you are in fact unleavened. For Christ our Passover also has been sacrificed. We are crucified to the world and it to us. It is no longer we who live but He who lives in us - provided He lives in us. Therefore let us celebrate the feast,
not with old leaven,
nor with the leaven of malice and wickedness,
but with the unleavened bread of sincerity and truth.