I can read about miracles in the Bible and not be amazed. The flannel graph presentations of my youth have made the stories so familiar that too often I do not connect with how radical the events actually were. This healing should amaze me but its familiarity masks how marvelous it really is.
If some could witness the miracles of Jesus and remain unconvinced and unconverted, we would be foolish to think that everyone will respond to our presentation and defense of the Gospel. The will overrides the intellect when dealing with matters of faith and world view. If the lack of response is an indication of failure, it is a failure that Jesus also experienced.