In the healing of the demoniac boy, context is important. The healing occurred immediately after the Transfiguration and the failure of the other disciples to cast out the demon. There is an important lesson for us. God is very near, even though we do not always (or even often) fell Him. Things can change in a moment. The Lord said to the man: “If thou canst believe, all things are possible to him that believeth.” How do we cultivate this belief? It is a very mysterious and holy thing, and required our effort, but only by God’s great mercy will we have powerful, life changing belief.
If thou canst believe, all things are possible to him that believeth.
orthodox.net