"Then they brought him [the demon possessed boy] to Him [Jesus]. And when he saw Him, immediately the spirit convulsed him, and he fell on the ground and wallowed, foaming at the mouth. So He asked his father, 'How long has this been happening to him?' And he said, 'From childhood. And often he has thrown him both into the fire and into the water to destroy him. But if You can do anything, have compassion on us and help us.' Jesus said to him, 'If you can believe, all things are possible to him who believes.' Immediately the father of the child cried out and said with tears, 'Lord, I believe; help my unbelief!' When Jesus saw that the people came running together, He rebuked the unclean spirit, saying to it: 'Deaf and dumb spirit, I command you, come out of him and enter him no more!' Then the spirit cried out, convulsed him greatly, and came out of him. And he became as one dead, so that many said, 'He is dead.' But Jesus took him by the hand and lifted him up, and he arose."
The suffering described by the father is witnessed at this time. Jesus asked the father how long this had been happening to his child, not because He didn't know but because He wanted to emphasize the genuine power of the healing that was about to take place. Apparently, it had been happening for quite some time. The evil spirit had nearly killed his son on many occasions by throwing him into dangerous places such as fire or water.
Without realizing it, the father here shows a weak faith - "But if You can do anything, have compassion on us and help us" (Mark 9:22). Jesus' power is questioned and the miracle now becomes a test of His power. Probably the failure of the apostles to heal his son weakened the faith the man originally had. Medically, the same thing happens today. When several doctors fail to cure us, it lessens our confidence in future efforts by others.
Jesus responded - "If you can believe, all things are possible to him who believes" (Mark 9:23). Interestingly, some manuscripts do not have the word "believe" in the first phrase. If this is correct, then Jesus is essentially echoing the words of this man - "If you can?!" Certainly Jesus could heal his son, but would the father believe in Him? That was the true question.
"Immediately the father of the child cried out and said with tears, 'Lord, I believe; help my unbelief!'" (Mark 9:24). The father understood Jesus to say that His son's cure would depend in part upon his willingness to believe (i.e., if the man didn't have faith in Jesus' power to heal his son, then Jesus would have chosen not to heal the boy). He emotionally confessed his faith but admitted that it was weak and needed to be strengthened. He asked that what was lacking in his faith be supplied to him. He desired to put His entire confidence in Jesus.
Let it be understood that even if the father didn't have faith in Jesus, that would not have made it impossible for Jesus to heal his son. This context teaches that a lack of faith on the part of a miracle worker will hinder the successful performing of a miracle (cf. Matt. 17:20). Elsewhere the New Testament provides many examples of people being healed miraculously when they didn't have any faith in the miracle worker (e.g., John 11:43,44; Acts 3:1ff; etc.). These facts must be pressed firmly when dealing with those who claim to work miracles today but try to blame their failures upon the individual's lack of faith.
Although a longer conversation with this man may have been beneficial, Jesus decided to act quickly since an even larger crowd was gathering. He commanded the spirit to come out of the boy and also restricted it from entering into him again. "Then the spirit cried out, convulsed him greatly, and came out of him" (Mark 9:26). The demon reluctantly obeyed the command of Jesus and, in so doing, attempted to destroy one whom he can no longer use.
Many pronounced the son dead, but he was merely exhausted from the violent nature of the exorcism. Jesus took him by the hand, lifted him up, and presented him in perfect health to his father.
The power and compassion of the Lord Jesus Christ is unparalleled! Praise God for such a wonderful Savior!