We see here that Jesus has just left the Pharisees and is warning his disciples to beware the leaven of the Pharisees. The disciples did not immediately understand this saying and were confused. They questioned amongst themselves saying, “We did not bring any bread.”
Jesus said to them did they not recall the times he fed the four thousand and fed the five thousand and how much bread was left over? It was only then they understood he was not talking about bread but by saying beware the leaven of the Pharisees he was telling them to beware the teachings of the Pharisees.
Let’s consider leaven for a moment. Leaven is yeast. A lump of leaven could also be a piece of dough that has had yeast added and is mixed in with a batch of dough. The purpose of leaven or yeast in bread making is threefold. Firstly, it causes the bread to rise. Yeast is a living substance with bacteria that give off carbon dioxide, which is the gas generated to cause the dough to rise. Secondly, it improves the taste and texture of the bread. Anyone who has had damper, which is an unleavened form of bread, will know that it is rougher in texture and tastes more floury or doughy than leavened bread. And finally it spreads and expands when put into flour. It gradually goes right through the bread and leavens it all.
Consider these aspects of leaven as they apply to the teachings of the Pharisees. First leaven causes bread to rise. In essence it puffs the bread up. The Pharisees were puffed up with pride and full of hypocrisy. They believed they had the knowledge of the kingdom and were the keepers of the kingdom of God, but they were wrong. As Jesus said in Matthew 23:14, “But woe to you, scribes and Pharisees, hypocrites! Because you shut the kingdom of heaven against men; for you neither enter yourselves, nor allow those who would enter to go in.” Paul also wrote of the puffery of knowledge saying, “We know that “all of us possess knowledge.” “Knowledge” puffs up, but love builds up.” (1 Corinthians 8:1) So the first warning Jesus was giving about the teachings of the Pharisees was that it leads to false pride and arrogance.
Now let us look at leaven in relation to the improvement of taste and texture. Often the false teachings that are offered are wrapped in a cloak of deceit. They sound good but they are destructive. Many New Age teachings are like this. As Paul wrote, “These have indeed an appearance of wisdom in promoting rigor of devotion and self-abasement and severity to the body, but they are of no value in checking the indulgence of the flesh.” (Colossians 2:23) He also spoke of these false teachers and their leaven-like teachings that would lead people astray. “For the time is coming when people will not endure sound teaching, but having itching ears they will accumulate for themselves teachers to suit their own likings, and will turn away from listening to the truth and wander into myths.” (2 Timothy 4:3-4) People will look for teachings that justify themselves rather than lead to the glory of God. They will seek things that they like to hear and look for people teaching this false doctrine.
Finally the invasive nature of leaven is like these false teachings, and the most dangerous aspect of these teachings and teachers. It is Satanic for he was the author of deceit and deception, the master of the lie and the half-truth. Paul showed this insidious leaven-like aspect of false teaching like this; “Avoid such godless chatter, for it will lead people into more and more ungodliness, and their talk will eat its way like gangrene. Among them are Hymenae’us and Phile’tus, who have swerved from the truth by holding that the resurrection is past already. They are upsetting the faith of some.” (2 Timothy 2:16-18) The greatest problem of the leaven-like teachings is that they are insidious. They will seep into a person and like leaven will colour all that a person believes, causing them to swerve from the truth as Paul wrote.
Jesus also showed this insidious nature of the false, hypocritical teachings of the Pharisees in the following parable. “The eye is the lamp of the body. So, if your eye is sound, your whole body will be full of light; but if your eye is not sound, your whole body will be full of darkness. If then the light in you is darkness, how great is the darkness!” (Matthew 6:22-23) If we look for what is not good, the darkness, and allow it into our minds, how greatly will it darken our life? We must shun the teachings of darkness and seek the light of the Lord that comes through the knowledge of Jesus Christ.
There are many teachings that Jesus uses to warn his people of the false teachings that will come. Jesus constantly warns us about wolves in sheep clothing, false teachers, false prophets and the problems of accepting the lies from these people. Instead we must focus on the teachings of God and weigh all things up against the words in the Bible. When in doubt, seek his guidance in prayer and make no decision until you learn the right path.