Why could we not drive the spirit out? He said to them, “This kind can only come out through prayer.” Jesus and the three disciples descended the mountain of the transfiguration only to find the other disciples embroiled in an argument with a section of a crowd that had formed around them. Apparently an epileptic boy had been brought to Jesus for healing, and in his absence, the task fell to his disciples who, unfortunately, were unable to do anything. The disciples’ inability to cure the boy drew a sharp rebuke from Jesus: “How long must I be with you, oh faithless generation?” Jesus was amazed at both the disciples’ and the boy’s father’s lack of faith. The disciples had watched Jesus perform such miracles before and, as anyone would ordinarily expect, they too might have longed for that day when they would be able to do as Jesus does. However, it appears the day dawned sooner than expected. For even though the disciples fired from all their cylinders, they were still unable to heal the boy. On his part, the boy’s father found himself on the receiving end of Jesus’ rebuke because of his skeptical tone: “If you can…”
Jesus attributed the disciples’ failure to lack of an “active” faith, that is, a faith that translates into action. The disciples did believe in Jesus. But their faith was “ungrounded,” so to speak. “Your faith must be grounded in prayer,” Jesus told them, “It is not enough that you believe in me. Your faith must also put you in communion with God through prayer. You must involve God in such efforts since it is God who works such signs in his people.” In addition, the disciples also had to believe in themselves, that is, in their ability to work signs in God’s name. It might be that their motive for wanting to help came from an attempt to gauge themselves and to see if God could perform signs through them (as God did through Jesus). They did believe, but their belief lacked trust (trusting faith). They had to trust in God, that just as God chose Jesus to be an instrument for healing, they too had been chosen as God’s instruments.