Matthew 17:18 WEB

¹⁶  So I brought him to your disciples, and they could not cure him.'

¹⁷  Jesus answered, 'Faithless and perverse generation! How long will I be with you? How long will I bear with you? Bring him here to me.'

¹⁸  Jesus rebuked him, the demon went out of him, and the boy was cured from that hour.

¹⁹  Then the disciples came to Jesus privately, and said, 'Why weren't we able to cast it out?'

²⁰  He said to them, 'Because of your unbelief. For most assuredly I tell you, if you have faith as a grain of mustard seed, you will tell this mountain, 'Move from here to there,' and it will move; and nothing will be impossible for you.