"I believe; help my unbelief!"

Here is the key to the lesson Jesus is teaching His disciples when they asked why they could not help the man and his boy. After all, they believed and Jesus had said that all things were possible to those who believed.

But the man did more than just believe. He believed and prayed.

Jesus said that deliverance from the oppressing demon that tormented the boy required prayer. Some manuscripts include, “and fasting.”

Prayer requires belief, but in this case, belief is verified and amplified through prayer. After all, the man declares, in His prayer to Jesus, that he does indeed believe, but he doubts the power of his own, weak, feeble, capacity to believe. He is honest, but he is also desperate.

His trust is like the one who believes enough to jump into the darkness even though he is still trembling with shades of uncertainty.

What took his belief beyond its own ability to believe was the declaration, “I believe,” followed by the prayer, “Help my unbelief.”

Mark 9:14-29 (NRSV)
When they came to the disciples, they saw a great crowd around them, and some scribes arguing with them. When the whole crowd saw him, they were immediately overcome with awe, and they ran forward to greet him. He asked them, "What are you arguing about with them?" Someone from the crowd answered him, "Teacher, I brought you my son; he has a spirit that makes him unable to speak; and whenever it seizes him, it dashes him down; and he foams and grinds his teeth and becomes rigid; and I asked your disciples to cast it out, but they could not do so." He answered them, "You faithless generation, how much longer must I be among you? How much longer must I put up with you? Bring him to me." And they brought the boy to him. When the spirit saw him, immediately it convulsed the boy, and he fell on the ground and rolled about, foaming at the mouth. Jesus asked the father, "How long has this been happening to him?" And he said, "From childhood. It has often cast him into the fire and into the water, to destroy him; but if you are able to do anything, have pity on us and help us." Jesus said to him, "If you are able!– All things can be done for the one who believes." Immediately the father of the child cried out, "I believe; help my unbelief!" When Jesus saw that a crowd came running together, he rebuked the unclean spirit, saying to it, "You spirit that keeps this boy from speaking and hearing, I command you, come out of him, and never enter him again!" After crying out and convulsing him terribly, it came out, and the boy was like a corpse, so that most of them said, "He is dead." But Jesus took him by the hand and lifted him up, and he was able to stand. When he had entered the house, his disciples asked him privately, "Why could we not cast it out?" He said to them, "This kind can come out only through prayer."