The story of Peter's confession of Jesus as the Christ is a turning point in the gospel of Matthew and serves as our passage for study.
 v13. Jesus has moved away from the crowds to minister to (teach) his disciples. Caesarea Philippi, at the base of Mount Hermon and some 50 kilometers North of Galilee, is a Gentile town, and Jesus has moved into territory near this city.
v14. Neither the crowds, nor the religious authorities, had come to recognize Jesus as the messiah. Herod Antipas, 14:2, thought he was John the Baptist risen from the dead. Many saw him as an Elijah figure, the promised prophet who precedes the messiah (the one crying in the wilderness). Others saw him as a Jeremiah figure, a prophet of doom, while others saw him as a prophet in general terms. In answering Jesus' question, the disciples mention only the positive opinions.
v15-16. Jesus pushes the disciples to articulate their own understanding. Peter's confession probably expresses the opinion of all the disciples, namely, that Jesus is the messiah, "the Christ", sent by God to save Israel. The term, "Son of God", is a messianic title meaning "the Anointed One," and is not referring to Christ's relationship with the Father. God is "the living God" in that he is the source and giver of life.
v17. Peter's knowledge that Jesus is the Christ is not human in origin. It is part of God's (general?) revelation to humanity. Now that Peter has observed it, he proclaims it.
v18. Jesus plays with Peter's name, which means rock, and declares that on this rock he will build his church. The "rock" is most likely the priority of Peter and his confession of faith. He is the first of many believers who will stand up for Jesus and so become members of an eternal community.
v19. Peter, as the first (in time) among many who will confess Jesus as "Son of the living God", is now described as the one who holds the keys of the kingdom. He, along with all those who follow in his footsteps, has the power to open the gates of the kingdom, or to close them, ie. give permission for people to enter the kingdom, or exclude people from it. This is done through the proclamation of the gospel and the entry, or exclusion, that follows either belief, or rejection.
v20. Jesus reminds his disciples to keep the "messianic secret." Jesus didn't try to conceal his messianic identity, but rather reveal it in such a way as to draw out the true seeker, while at the same time confuse those opposed to the dawning kingdom. An overt disclosure would draw out many who were looking for a political leader to throw out the Romans.
 There is a sense where every Christian is a member of the "catholic" church. For example, the English Prayer Book uses the term "catholic" in a particular Biblical sense meaning "universal" - "the whole Catholick Church of Christ". Catholic then means all believers everywhere of whatever denomination - Christ's church universal; all believers past, present and future.
In the New Testament, the word "church" means assembly, Christian or otherwise. Today the term is used exclusively of a Christian assembly. You can't have a Hindu church, although you can have a Hindu assembly. Although we are members of the one church, it has two forms. There is the local assembly we gather with regularly - daily, weekly, monthly.... whatever. There is no requirement on how often we meet, just that we "don't forsake the gathering together of the brotherhood". As we meet, Jesus is present with us. This is his promise. The other form of the church is the heavenly gathering with Christ. Although we await the resurrection of the dead, there is a sense where even now we are "raised up with Christ and seated with him in the heavenly realms", Eph.2:6. At the day of resurrection we will all gather at the same moment, to be with Christ for eternity. That reality is so real that the apostle can speak of it as a present reality. This then is the catholic church, the universal Christian church. When we gather with our brothers and sisters in the Lord, we mimic the eternal gathering of all God's people. As we gather we are part of an eternal whole.
The church that Jesus tells Peter he is about to build, is the universal eternal community of believers. Jesus' words to Peter tell us something of this church.
i] Membership is gained by confessing Christ. Christ's eternal community is made up of those who trust him for their eternal security. There are no other entrance requirements. When we trust Jesus, "the Son of the living God", we are eternally secure in him.
ii] Christ's community is eternal. It is not a religious fad which will fade out with the passing of time. Nor can spiritual powers of evil overcome Christ's eternal community.
iii] Christ's community is functional. Each individual member of Christ's fellowship has both the authority and responsibility to offer God's forgiveness and total acceptance to all who seek his mercy in Christ.
When we have a big-picture view of the church we need no longer feel alone, vulnerable or afraid.
 1. What is the "rock", "the gates of Hades" and the "keys"?
2. How is Jesus using the word "church" in this passage and how does it result in a high view of the church?