Matthew 17:9-21

9Now as they came down from the mountain, Jesus commanded them, saying, “Tell the vision to no one until the Son of Man is risen from the dead.”

10And His disciples asked Him, saying, “Why then do the scribes say that Elijah must come first?”

11Jesus answered and said to them, “Indeed, Elijah is coming first and will restore all things.

12But I say to you that Elijah has come already, and they did not know him but did to him whatever they wished. Likewise the Son of Man is also about to suffer at their hands.”

13Then the disciples understood that He spoke to them of John the Baptist.

14And when they had come to the multitude, a man came to Him, kneeling down to Him and saying,

15“Lord, have mercy on my son, for he is an epileptic and suffers severely; for he often falls into the fire and often into the water.

16So I brought him to Your disciples, but they could not cure him.”

17Then Jesus answered and said, “O faithless and perverse generation, how long shall I be with you? How long shall I bear with you? Bring him here to Me.”

18And Jesus rebuked the demon, and it came out of him; and the child was cured from that very hour.

19Then the disciples came to Jesus privately and said, “Why could we not cast it out?”

20So Jesus said to them, “Because of your unbelief; for assuredly, I say to you, if you have faith as a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; and nothing will be impossible for you.

21However, this kind does not go out except by prayer and fasting.”