Matthew 17:18-20

18Then Jesus rebuked the demon, and it came out of him, and from that moment the boy was healed.

19Then the disciples approached Jesus privately and said, “Why couldn’t we drive it out?”

20“Because of your little faith,” he told them. “For truly I tell you, if you have faith the size of a mustard seed, you will tell this mountain, ‘Move from here to there,’ and it will move. Nothing will be impossible for you.”