1. Jesus heals a boy with an evil spirit that his disciples could not heal. When Jesus rebukes the spirit, it throws the boy into convulsions but Jesus heals him. 2. The disciples ask Jesus privately why they could not heal the boy, and Jesus says this kind of spirit can only be driven out through prayer. 3. The passage addresses the struggles some have with faith, including the problem of evil, the perceived impotence of Christians, and realizing one's own lack of faith. True faith is ultimately a decision to believe in Jesus.