Mark 9:19-23

And he answered them, “O faithless generation, how long am I to be with you? How long am I to bear with you? Bring him to me.” And they brought the boy to him. And when the spirit saw him, immediately it convulsed the boy, and he fell on the ground and rolled about, foaming at the mouth. And Jesus asked his father, “How long has this been happening to him?” And he said, “From childhood. And it has often cast him into fire and into water, to destroy him. But if you can do anything, have compassion on us and help us.” And Jesus said to him, “‘If you can’! All things are possible for one who believes.”