Matthew 17:14-21

14 And when they were come to the multitude, there came to him a certain man, kneeling down to him, and saying,

15 Lord, have mercy on my son: for he is lunatick, and sore vexed: for ofttimes he falleth into the fire, and oft into the water.

16 And I brought him to thy disciples, and they could not cure him.

17 Then Jesus answered and said, O faithless and perverse generation, how long shall I be with you? how long shall I suffer you? bring him hither to me.

18 And Jesus rebuked the devil; and he departed out of him: and the child was cured from that very hour.

19 Then came the disciples to Jesus apart*, and said, Why could not we cast him out?

20 And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.

21 Howbeit this kind goeth not out but by prayer and fasting.