Matthew 17:10-20

10 "Why then," asked the disciples, "do the Scribes say that Elijah must first come?"

11 "Elijah was indeed to come," He replied, "and would reform everything.

12 But I tell you that he has already come, and they did not recognize him, but dealt with him as they chose. And before long the Son of Man will be treated by them in a similar way."

13 Then it dawned upon the disciples that it was John the Baptist about whom He had spoken to them.

14 When they had returned to the people, there came to Him a man who fell on his knees before Him and besought Him.

15 "Sir," he said, "have pity on my son, for he is an epileptic and is very ill. Often he falls into the fire and often into the water.

16 I have brought him to your disciples, and they have not been able to cure him."

17 "O unbelieving and perverse generation!" replied Jesus; "how long shall I be with you? how long shall I endure you? Bring him to me."

18 Then Jesus reprimanded the demon, and it came out and left him; and the boy was cured from that moment.

19 Then the disciples came to Jesus privately and asked Him, "Why could not we expel the demon?"

20 "Because your faith is so small," He replied; "for I solemnly declare to you that if you have faith like a mustard-seed, you shall say to this mountain, `Remove from this place to that,' and it will remove; and nothing shall be impossible to you.