When they went across the lake, the disciples forgot to take bread. "Be careful," Jesus said to them. "Be on your guard against the yeast of the Pharisees and Sadducees." They discussed this among themselves and said, "It is because we didn’t bring any bread." Aware of their discussion, Jesus asked, "You of little faith, why are you talking among yourselves about having no bread? Do you still not understand? Don't you remember the five loaves for the five thousand, and how many basketfuls you gathered? Or the seven loaves for the four thousand, and how many basketfuls you gathered? How is it you don't understand that I was not talking to you about bread? But be on your guard against the yeast of the Pharisees and Sadducees." Then they understood that he was not telling them to guard against the yeast used in bread, but against the teaching of the Pharisees and Sadducees. - Matthew 16:5-12

Jesus, with his disciples, was leaving the Pharisees and Sadducees after telling them they would have no miraculous sign except the sign of Jonah. As they crossed the Sea of Galilee, Jesus made a subtle reference to yeast. The disciples thought he was talking about bread, but Jesus was actually talking about the teaching of the Pharisees and Sadducees. The Pharisees believed that people get to heaven by making themselves pure before God by not breaking God’s commandments and keeping their religious rules. The Sadducees didn't believe in heaven or hell, but were very strict about obeying the Old Testament laws.

One group tried to get to heaven on its own; the other group didn't believe in heaven at all. Neither was right. There certainly is a heaven, but we can't get there on our own. The "yeast" of bad theology can keep us from seeing that Jesus himself is the only way to heaven. That's the yeast we need to sweep out of our hearts, and let Jesus be Jesus -- who died and rose to give us eternal life in heaven.

Jesus held up two of his most recent miracles to make his point that we can rely on him completely for salvation. Why? He is God! He is the one who can do anything, and who has done the most amazing things for us. He performed miracles out of compassion, he performed miracles to prove that he is God’s Son who came from heaven, and he performed miracles to show God's stamp of approval on him as the world’s Savior.

Take to heart his words of saving truth: "I am the way and the truth and the life. No one comes to the Father except through me" (John 14:6).