It is probably not coincidence that it is in Caesarea Philippi that Jesus questions his disciples about his identity. The name itself tells us quite a bit about this city. It bears both a name from Roman government (Caesar) and Jewish royalty (Philip, son of Herod the Great). In it, stood a temple built for Caesar by Herod the Great. It is a city that represents not only power, but specifically Rome's seemingly unconquerable power and the collusion of Jewish leadership with it. In other words, this city is probably representative of just about everything that 12 Jewish men might be hoping a Messiah would deliver them from. And it is here that Jesus asks "Who do people say that the Son of Man is?"
The disciples share with Jesus a quick synopsis of public opinion regarding him. "Some say John the Baptist, others say Elijah, and others Jeremiah or one of the prophets." While we often think of these as the wrong answer as compared to Peter's confession two verses later, they are actually instructive in themselves. Jesus' ministry looked very much like those of these prophets. He went around speaking God's word to the people of Israel much like Jeremiah and the prophets, performing powerful signs and miracles like Elijah, and living an unsettled existence somewhat like John the Baptist. Jesus often compares his own ministry to the prophets in that he will be rejected as they were. So its not that these answers are so much wrong as incomplete. Jesus is certainly "a prophet mighty in deed and word before God and all the people" but he is also more than that.
Jesus now turns the question to the disciples themselves. "But who do you say that I am?" Peter, probably eager to distinguish himself, answers "You are the Christ, the Son of the living God." Now what was incomplete in the crowds understanding of Jesus has been made complete in Peter's confession. Jesus is the Christ, the Messiah, the Son that God has chosen to be Israel's deliverer. Peter's confession has hit the bull's eye of Christ's identity; so much so that Jesus says this was revealed to Peter by God, not by human deduction. Indeed, Jesus proclaims that Peter (whose name means "rock") is the rock on which Christ will build his Church, a Church so powerful that the gates of hell shall not prevail against it. (If you are a fan of Lord of the Rings, just picture Aragorn and his army standing before the gates of Mordor.) This Church, of which Peter is the foundation, apparently even has the ability to impact heaven through its earthly ministry (whatever you bind on earth shall be bound in heaven...).
But for all that Peter gets right (and Matthew's certainly wants us to see that his confession really is significant), there is still much he does not understand. The very next thing that Jesus does after affirming Peter's confession of him as the Christ is to begin to talk about his suffering and death. Understandably, Peter takes Jesus aside to remind him that he can't talk like this. After all, it was just settled that Jesus was the Messiah which means he is a conquering hero, not someone who will suffer and die. But Jesus knows he is going to be an entirely different kind of Messiah, one who will look much more like Jeremiah than David. So he tells his disciples not only that he will die but that if they truly want to follow him they must deny themselves and take up their own cross as well.
Monuments to power fill our own world. Often these powers are so overwhelming that we feel our only hope is either collusion or open conflict. In the midst of these monuments of power, Jesus question to us is whether or not we know him. Of course, we think that we do. While our culture may label him as merely a prophet like others, we know that he is more, that is the Christ the Son of the living God. But then the real challenge when Jesus wants to show us what he means by that word "Christ" and what he means when he call us "disciples". This Messiah and his followers will not be defined but yet another monument of power but by one of a weakness. To truly confess Jesus, to truly know who Jesus is, is take up our own cross, our own denial and follow him in a life of sacrifice and service.