Our Lord made quite a play on words in replying to Peter’s confession.
Not only is the statement that Jesus is the Son of God the rock, or foundation, upon which all of Christianity rests, but Jesus and the disciples were at Caesarea Phillippi, a city whose chief landmark is a very large and well-known rock cliff.
So Jesus’s words were a loving and, most likely, playful pun: Peter, a name that means “rock,” standing near a huge natural rock, uttering the confession upon which the Church still stands today. Beautiful.
http://www.ancientsandals.com/overviews/caesarea_philippi.htm
This would be the only biblical case then, where God changed the name of a person without effecting a major change in that person's life (e.g. Abram to Abraham, Jacob to Israel, and Saul to Paul).
Is there a sufficient justification for rejecting biblical precedent?
What if Jesus is elevating Rock (Peter) to the vice-regency (vice-king/prime minister) of the eternal Davidic kingdom, of which Jesus is king?
In fact, this can be proven from Scripture. We know from the Old Testament that the position of vice-regent of the House of David existed, and that its authority was represented by an oversized key which the vice-regent wore around his neck.
Isaiah 22:22In Revelation 3:7, we see that Jesus is the eternal king of the house of David, or "the power behind the keys."I will place on his shoulder the key to the house of David; what he opens no one can shut, and what he shuts no one can open.
Revelation 3:7In Matthew, we see Jesus, the eternal king of the House of David, giving the keys of the eternal Davidic kingdom (the key of the vice-regency) to Rock (Peter)."To the angel of the church in Philadelphia write: These are the words of him who is holy and true [Jesus], who holds the key of David. What he opens no one can shut, and what he shuts no one can open."
Matthew 16:19Jesus changes Simon's name to Rock when he elevates him to the position of vice-regent of the eternal Davidic kingdom (i.e., the head of Christ's Church, "the pillar and foundation of truth").I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven."
Sorry for repeating the point I made earlier. Bump confusion...