14 And when they were come to the multitude, there came to him a certain man, kneeling down to him, and saying, 15 Lord, have mercy on my son: for he is lunatic, and sore vexed: for ofttimes he falleth into the fire, and oft into the water. 16 And I brought him to thy disciples, and they could not cure him. 17 Then Jesus answered and said, O faithless and perverse generation, how long shall I be with you? how long shall I suffer you? bring him hither to me. 18 And Jesus rebuked the devil; and he departed out of him: and the child was cured from that very hour. 19 Then came the disciples to Jesus apart, and said, Why could not we cast him out? 20 And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you. 21 Howbeit this kind goeth not out but by prayer and fasting. (Matthew 17:14-21)
Jesus Heals a Boy with a Demon
We witness here the miraculous healing of a child who was mentally disturbed and tormented by a demon. This occurred just after Jesus descended from the mountain where he was transfigured (Matthew 17:1-13). His glorious experience did not make him distant—he remained approachable and compassionate. As soon as he returned from communing with Moses and Elijah, he was met by human need.
The boy’s father came kneeling before Jesus with an intense, heartfelt plea. A deep awareness of suffering often brings people to their knees and drives them to seek Jesus earnestly—and he welcomes that kind of faith. The father raised two main concerns:
First, the suffering of his son (Matthew 17:15): “Lord, have mercy on my son.” A child’s suffering deeply affects any loving parent. This boy’s condition left him unable to seek help himself, so his father interceded. Parents have a special responsibility to pray for their children, especially those too weak or unwilling to seek God. The boy was severely troubled, likely with epilepsy, worsened or caused by a demon. The symptoms were extreme—he often fell into fire and water—showing the destructive intent of the devil. Jesus, however, didn’t just address the symptoms; he rebuked the demon, attacking the root cause. As 1 Peter 5:8 reminds us, Satan seeks to devour—but Christ delivers.
Second, the failure of the disciples (Matthew 17:16): “I brought him to your disciples, but they couldn’t heal him.” Though Jesus had given them authority over demons (Matthew 10:1, 8), and they had previously succeeded (Luke 10:17), they failed this time. Jesus allowed it to humble them and to glorify his own power. Sometimes, Christ lets other sources disappoint us so that we will turn directly to him. People may fail—but his grace never does.
Jesus responded with two rebukes—first to the people, then to the demon.
He said (Matthew 17:17), “O faithless and twisted generation!”These words were directed more to the crowd, likely including the scribes (see Mark 9:14), who had mocked the disciples’ failure. Unbelief hindered the work of God. The people’s lack of faith blocked blessings, just as the disciples’ weak faith limited their power. Faith aligns us with God; unbelief opposes him (Deuteronomy 32:20; Psalm 95:9).
Jesus asked, “How long will I be with you? How long must I put up with you?”—expressing sorrow over their spiritual immaturity and persistent unbelief. Though he had been patient with Israel (Acts 13:18), that patience had a limit. Yet, in compassion, he said, “Bring him here to me.” Even when others fail, we can turn to Christ—his power and mercy are never exhausted.
Jesus then healed the child by rebuking the demon (Matthew 17:18). The healing was immediate and complete, demonstrating his authority and compassion. Christ broke Satan’s power, offering hope to all who struggle spiritually (Colossians 2:15). The Lion of Judah conquers the roaring lion.
Later, the disciples asked Jesus privately why they had failed (Matthew 17:19). Ministers must maintain private communion with Christ, acknowledging weaknesses and seeking instruction. Jesus gave two reasons:
First, their lack of faith (Matthew 17:20): He had rebuked the father and crowd for their unbelief, and now he addressed the disciples’ as well. Everyone had faults, but it’s more important to recognize our own. When ministry doesn’t seem effective, people often blame each other, but both sides should humbly examine themselves.
Jesus said, “If you have faith the size of a mustard seed… nothing will be impossible.” Even a small amount of genuine faith could have prevailed. The issue was not the size of their faith, but its absence at a critical moment. Perhaps they doubted whether their authority still applied after Jesus took only three of them up the mountain. True faith relies not on circumstances, but on Christ’s enduring promise. Doubting ourselves may be healthy, but doubting Christ’s power displeases him.
Second, the difficulty of the case (Matthew 17:21): “This kind does not come out except by prayer and fasting.” Some demons are more aggressive or deeply rooted—especially when connected to physical conditions like epilepsy. Such cases require deeper spiritual preparation. Not all spiritual challenges are equal. The more intense the opposition, the more intense our faith and prayer must be. Some interpret what Jesus said to mean that the kind of faith needed for victory over this demon comes only through devoted prayer and fasting. Fasting disciplines the body and sharpens the soul for spiritual battle. When Satan exploits our physical weaknesses, fasting may help break his hold.