Matthew 17:14-20

When they returned to the crowd, a man came to Jesus, knelt before him, and said, “Sir, have mercy on my son! He is an epileptic and has such terrible attacks that he often falls in the fire or into water. I brought him to your disciples, but they could not heal him.” Jesus answered, “How unbelieving and wrong you people are! How long must I stay with you? How long do I have to put up with you? Bring the boy here to me!” Jesus gave a command to the demon, and it went out of the boy, and at that very moment he was healed. Then the disciples came to Jesus in private and asked him, “Why couldn't we drive the demon out?” “It was because you do not have enough faith,” answered Jesus. “I assure you that if you have faith as big as a mustard seed, you can say to this hill, ‘Go from here to there!’ and it will go. You could do anything!”