In the midst of a chapter discussing the contrasts between Jesus’ true identity and the expectations many had of the Messiah, we read, “Then Jesus said to them, “Take heed and beware of the leaven of the Pharisees and the Sadducees” (Mt. 16:6).

Leaven is yeast, a single-celled fungus that is a key ingredient in many baking recipes. The process of leavening bread with yeast begins with the activation of the yeast. This is done by combining the yeast with warm water and a small amount of sugar. The sugar provides the yeast with the energy it needs to begin the process of fermentation. As the yeast consumes the sugar, it produces carbon dioxide gas, which is trapped in the dough and causes it to expand. Once the dough has risen, it is ready to be baked. The heat of the oven causes the carbon dioxide gas to expand further, creating a light and airy texture in the finished product. Leaven is used in the Bible as a metaphor for an unseen pervasive influence, usually evil.

The disciples had their minds on physical bread, worrying that they had not brought any with them on their journey (Mt. 16:5). Perhaps they had forgotten to because of their anxiety regarding the confrontation with the religious leaders prior to their departure. Jesus admonished them for their lack of faith, reminding them of the occasions where He had miraculously multiplied bread (Mt. 16:8-10). Jesus restated His warning (Mt. 16:11), then the disciples understood that the point was not bread, but rather the doctrine of the Pharisees and Sadducees (Mt. 16:12).

The Pharisees were an important Jewish sect in the time of Jesus. They were insistent on an exact observance of the oral traditions which spelled out how to keep the law, but were not very involved in the politics of the day. The Sadducees, on the other hand,  were a major force in the politics of Judea during the time of Jesus; Mark’s parallel account which has “leaven of Herod” instead of “Sadducees” may speak to this (Mk. 8:15). The Sadducees were the ruling class in control of the Temple and the Sanhedrin. The Sadducees were known for their literal interpretation of the Torah and their rejection of the oral law and the teachings of the Pharisees. While the Pharisees and Sadducees were often at odds, they were united in opposition to Jesus. Together they tested Jesus at the beginning of this chapter (Mt. 16:1).

Jesus went on to speak of establishing His kingdom where what was bound and loosed in heaven would be bound and loosed upon earth (Mt. 16:19). While the Pharisees and Sadducees had many differences—they bound and loosed different rules—their uniting together to resist God’s Messiah showed their biases prevented them from seeing what God was clearly communicating right in front of them. Religious traditions and political loyalties are some of the most pervasive and difficult forces to overcome in people being honest with the Word of God and truly following Him. We would not for a minute tolerate poison being laced into our daily food that sustains us physically; however, with our spiritual nourishment—that should sustain our eternal souls to live eternally—far too many consume false religious teaching and political lies to their own ruin. If we are going to enter the narrow gate that leads to life, we must beware of false teachers (Mt. 7:13-15).