When the disciples saw the transfiguration of Jesus on the mountain, all the questions were irrelevant in that light. It seemed to them that from now on they would not stumble in anything, everything was clear, the experience of God's presence carried them long after. But only until they descended from God's heights into the valley of darkness to an obsessed boy from whom they could not cast out demons. Here their faith met the spiritual reality of this world. This was a spiritual crisis - when it is impossible to go any further, neither knowledge nor past experience is enough, however famous they might have been. It even seems possible to say that a spiritual crisis occurs when reality is at odds with what has worked for us so far in our pursuit of God and denies it.