Be on your guard against the yeast of the Pharisees, which is hypocrisy.
Jesus used an ordinary baking ingredient (yeast) to picture the power of sin in people’s lives. It was Passover, and thousands of Jews were traveling to Jerusalem to celebrate this great feast commemorating their deliverance from slavery in Egypt. As part of their preparation for this event, people removed all of the yeast from their homes (Exodus 12:14-20).
Jesus knew how to use current events to make a point. With people paying so much attention to yeast, he pointed out that the sin of hypocrisy could be just as penetrating as yeast in bread, working its way to affect every inch of life.
In this way Jesus warned his disciples against being hypocrites in their service to God. Discipleship was and is serious business. There is no such thing as being “on the fringe” or neutral. We can easily find ourselves not living our real identity in the one true Savior.
True discipleship will involve suffering and self-denial. Choosing to do the will of God becomes more important than rejection or popularity. Discipleship means making people a priority rather than rituals and traditions. Loving your enemies pleases Jesus more than loving only your friends and family. Following Jesus means caring for the needy rather than giving priority to the rich, influential, and powerful. Jesus calls us to deny ourselves and follow him if we would truly be his disciples. Can we do that?