Matthew 17:18-20

17:18 Then Jesus rebuked the demon and it came out of him, and the boy was healed from that moment. 17:19 Then the disciples came to Jesus privately and said, “Why couldn’t we cast it out?” 17:20 He told them, “It was because of your little faith. I tell you the truth, if you have faith the size of a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; nothing will be impossible for you.”