How do you respond to John 21:18–19?

Jesus says to Peter, “‘[W]hen you were younger, you used to fasten your own belt and to go wherever you wished. But when you grow old, you will stretch out your hands, and someone else will fasten a belt around you and take you where you do not wish to go.’ (He said this to indicate the kind of death by which he would glorify God.) After this he said to him, ‘Follow me.’”

For providential reasons (undoubtedly connected with the encouragement of martyrs in the early church) God determined that Peter would suffer the same sort of death Christ suffered. Now that Peter had been humbled and had learned how to love and serve as Jesus loved and served (see How do you respond to Matt. 26:36) Jesus was going to teach him to die as Jesus died.

This prophecy suggests that by this time the Lord was going to providentially ensure that Peter would not die in any other fashion. This would obviously be a small feat for the Lord of the universe. But it does not suggest that everything else about Peter’s future was settled, still less that everything about the future of the world is settled. We only need to resort to the “crystal ball” understanding of omniscience when we lose our confidence in the Father’s providential wisdom in history and his ability to creatively achieve his objectives while allowing creatures to be free.