keys to the kingdom

Matthew 16:17-20

This is Jesus' response to Peter saying that Jesus was the Messiah, the Son of the Living God. The key words are rock, keys, bind and loose. Jesus draws a direct link between what Peter does on earth and what happens in heaven to indicate the extreme authourity that he is giving Peter. At least I think it is to Peter. My Bible doesn't differentiate between the plural you and the singular you. If it is plural, then this authourity is given to the disciples as a group.
There have been lots of debates as to what Jesus is talking about when he says he will build his church on this rock. The question is, what is the rock. Some people say that the rock is Jesus which is what the writer of Hebrews talks about when he describes Jesus as the rock which the builders rejected becoming the chief cornerstone of the Church. However, in context, to make this work Jesus has to be saying, "You are right Peter. I am the Messiah and on this rock (the Messiah) I will build..." This is a bit awkward and negates the play on words between Peter adn rock (although some would say that Jesus is not comparing Peter and rock but contrasting Peter - stone - and rock).
Some people say that Peter is the rock upon which Jesus will build the Church. This fits well in the context and with the play on words that Jesus uses. There is even evidence for this in Acts - Peter was often, maybe even always, the one who went to the new regions to release the Holy Spirit and welcome the new believers into the Kingdom of God. Protestants are hesitant to emphasize the role of Peter in reaction to the Catholic position on Peter.
The third position is that Jesus is talking about Peter's confession - Jesus will build his Church on the confession that Jesus is the Messiah. To me, this seems like too much of a compromise position: we know it isn't Jesus who is the Rock but we don't want it to be Peter so...
Obviously this is a passage that I need to do some more reading and study on. However, even with my questions, I am encouraged because Jesus will build his church. It belongs to him, he takes responsibility for its growth and he promises that it will be built. I am also challenged by the role that I play in joining Jesus in building his Church. The method he has choses is through the sharing of the gospel with the world and he has annointed me to be a messenger of that gospel. I am his amabassador and I must speak and act in accordance with that office.