Coming down from the mountain of transfiguration, Jesus meets a man with a severely afflicted son who His disciples were unable to cure. Later, in answer to their question about why they unable to cast out the demon He tells them, "It was because of your little faith. What you really need is the faith of a mustard seed." But, isn't that just another way of saying the same thing? What is Jesus driving at? Find out in this expository sermon from Matthew 17:14-21.