Mark 9:19-23

He answereth him, and saith, O faithless generation, how long shall I be with you? how long shall I suffer you? bring him unto me.

And they brought him unto him: and when he saw him, straightway the spirit tare him; and he fell on the ground, and wallowed foaming.

And he asked his father, How long is it ago since this came unto him? And he said, Of a child.

And ofttimes it hath cast him into the fire, and into the waters, to destroy him: but if thou canst do any thing, have compassion on us, and help us.

Jesus said unto him, If thou canst believe, all things are possible to him that believeth.