Later, the disciples approached Jesus and asked him privately, “Why couldn’t we drive out the spirit?” Jesus said to them, “Because you have little faith. I say to you: if only you had faith the size of a mustard seed, you could tell that mountain to move from here to there, and the mountain would obey. Nothing would be impossible for you.
It is quite clear in the ministry of Jesus that faith is a necessary condition for a miraculous healing. Genuine and strong faith must be manifested by the healer and the one being healed, or at least by the one asking for a miracle. In today’s Gospel story the disciples did not seem to have the kind of deep-hearted faith that would give them the power to drive out the evil spirit which possessed the boy. Jesus was somewhat disappointed by the disciples’ lack of genuine faith in God and in what they were capable of doing in his name.
If they were to continue the ministry of Jesus to heal and exorcise evil spirits, he speaks of the need for the disciples to have a faith that can move mountains. Faith is more than an intellectual assent to ideas, concepts or teachings. It is a relationship with God based on trust. This is accompanied by a confidence filled with certainty that “God will always give us what we need, protect us from evil and lead us to life everlasting.” The presence of a profound faith in God will enable the believer to do even the humanly impossible including “moving mountains.”