A man came up to Jesus and went down on his knees before him. ‘Lord,’ he said ‘take pity on my son: he is a lunatic and in a wretched state; he is always falling into the fire or into the water. I took him to your disciples and they were unable to cure him.’ ‘Faithless and perverse generation!’ Jesus said in reply ‘How much longer must I be with you? How much longer must I put up with you? Bring him here to me.’ And when Jesus rebuked it the devil came out of the boy who was cured from that moment.

Then the disciples came privately to Jesus. ‘Why were we unable to cast it out?’ they asked. He answered, ‘Because you have little faith. I tell you solemnly, if your faith were the size of a mustard seed you could say to this mountain, “Move from here to there,” and it would move; nothing would be impossible for you.’