[Jesus] cautioned them, saying, “Watch out; beware of the leaven of the Pharisees and the leaven of Herod.” Mark 8:15
The disciples are in the boat with Jesus crossing the lake. Nobody had thought about what they are going to do for lunch (8:14).
Jesus uses the boat trip to teach the disciples about the power of evil in the world. He warns them, “Beware of the leaven of the Pharisees and the leaven of Herod” (8:15). Yeast is often used as a figure of evil influence in the Bible, so Jesus is saying, “Watch out for the evil influence of the Pharisees and of Herod.”
Think about the opportunity here: God in the flesh is so near that the disciples can touch Him. Where might you have gone with that conversation? “Jesus, how should we respond to evil in the world? What should we do about false teaching or about the evils in government and business? How can we keep ourselves pure? How can we be like you?”
Instead, the disciples slide into a pointless discussion about having no bread. But Jesus gives it to them straight: “Do you not yet perceive or understand? Are your hearts hardened? Having eyes do you not see, and having ears do you not hear? And do you not remember?” (8:17-21).
Jesus reminds them of all the leftover bread after He fed the crowds (8:19-21). There must have been a long silence in the boat after that!
Eventually, the disciples do see and understand. Mark tells us about Peter’s great confession after Jesus asked them, “Who do people say that I am?” At last, Peter answers, “You are the Christ” (8:27-29).
This is a saving moment. When you believe in Jesus and confess Him as your Christ (your Savior), your whole relationship with God changes.
Have you, like the disciples, found yourself stuck in pointless discussions with Jesus?