When they returned to the other disciples, they saw a large crowd surrounding them, and some teachers of religious law were arguing with them. When the crowd saw Jesus, they were overwhelmed with awe, and they ran to greet him.
“What is all this arguing about?” Jesus asked.
One of the men in the crowd spoke up and said, “Teacher, I brought my son so you could heal him. He is possessed by an evil spirit that won’t let him talk. And whenever this spirit seizes him, it throws him violently to the ground. Then he foams at the mouth and grinds his teeth and becomes rigid. So I asked your disciples to cast out the evil spirit, but they couldn’t do it.”
Jesus said to them, “You faithless people! How long must I be with you? How long must I put up with you? Bring the boy to me.”
So they brought the boy. But when the evil spirit saw Jesus, it threw the child into a violent convulsion, and he fell to the ground, writhing and foaming at the mouth.
“How long has this been happening?” Jesus asked the boy’s father.
He replied, “Since he was a little boy. The spirit often throws him into the fire or into water, trying to kill him. Have mercy on us and help us, if you can.”
“What do you mean, ‘If I can’?” Jesus asked. “Anything is possible if a person believes.”
The father instantly cried out, “I do believe, but help me overcome my unbelief!”
When Jesus saw that the crowd of onlookers was growing, he rebuked the evil spirit. “Listen, you spirit that makes this boy unable to hear and speak,” he said. “I command you to come out of this child and never enter him again!”
Then the spirit screamed and threw the boy into another violent convulsion and left him. The boy appeared to be dead. A murmur ran through the crowd as people said, “He’s dead.” But Jesus took him by the hand and helped him to his feet, and he stood up.
Afterward, when Jesus was alone in the house with his disciples, they asked him, “Why couldn’t we cast out that evil spirit?”
Jesus replied, “This kind can be cast out only by prayer.”