Spockrates,
Catholics believe that Peter is the rock referred to in Matt 16:18. We also believe that Jesus Christ is a rock, and He is the chief cornerstone of the Church. We also believe that the Church is built on the foundation of apostles and prophets. The Bishop of Rome, the successor of the apostle Peter, is the visible head of the Church, the physical symbol of unity of the Church. Jesus Christ is the ultimate head of the Church, and is the ultimate symbol of unity. We believe that the Eucharist, the actual body and blood of Christ, is the most sacred way that we can commune with each other, and with Jesus Christ.
Catholics believe that Matthew 16:18 shows a very clear poetic structure, and in Greek and Aramaic, this is made even more clear. The name “Peter” means “rock”. We believe that Simon was named Peter/Rock for a reason, and when we understand that the passage reads “You are Rock, and on this rock I will build my church…”(emphasis mine), we can see that Jesus is referring to Peter when He is talking about a rock. There was no need to say “thee” or anything of the sort instead of “this”, since we can now see that Peter means rock, and this is just one of the many poetic ways that the Bible tells us various messages.
Now, this has multiple meanings for Catholics. We believe that Peter and his successors all had and have primacy in the Church. Catholics believe that Peter had primacy among the apostles, and his successors had and have primacy among the bishops. The Pope is a bishop (remember, one is not ordained a Pope, since the only three Orders in Catholicism are deacon, priest, and bishop). While Jesus Christ is the head of the Church, the chief cornerstone, Peter and his successors are the visible heads of the Church, and this is important to us in many ways.
Peter as the rock also refers to his faith as well. Pope John Paul II gave a great homily on the Solemnity of Saints Peter and Paul called “The Church is Built on Peter’s Faith and Fidelity”. Here are some important parts for you, and I think they will show the depth to which Catholics interpret Matthew 16:18, and why many of us are also amused/confused when others criticize our interpretation of the passage:
*" We are reflecting on this extraordinarily rich Gospel passage: the incarnate Word had revealed the Father to his disciples; now is the moment when the Father himself reveals his only Only-begotten Son to them. Peter receives inner enlightenment and courageously proclaims: “You are the Christ, the Son of the living God!”.
These words on Peter’s lips come from the depths of God’s mystery. They reveal the intimate truth, the very life of God. And Peter, under the action of the divine Spirit, becomes a witness and confessor of this superhuman truth. His profession of faith thus forms the firm basis of the Church’s faith: “On this rock I will build my Church” (Mt 16:18). The Church of Christ is built on Peter’s faith and fidelity.
…
Could Saul have understood with his reason alone all that such an event entailed (referring to Acts 9)? Certainly not! It was, in fact, part of God’s mysterious plan. It would be the Father who would give Paul the grace of knowing the mystery of the redemption accomplished in Christ. It would be God who would enable him to understand the marvellous reality of the Church, which lives for Christ, with Christ and in Christ. And he, who had come to share in this truth, would continuously and tirelessly proclaim it to the very ends of the earth."*
So, Catholics believe that Peter/Rock is the rock referred to in Matt 16:18. And why is he the rock? Because of his faith, which led him to his revelation, which came from God through Jesus Christ, who is the chief cornerstone. Peter had primacy among the apostles, and that primacy continues today in his successors, in Catholic belief. Peter would have been nothing without Jesus Christ, who is the most important rock of the Church, and who unity ultimately is found in in the Church, symbolized in the Eucharist.
Spockrates, like Peter, you too can receive knowledge from God about the truth of His Church. You can read and read and read, and ask us many questions, however you have to pray to God sincerely to find the truth. It all ultimately comes through Jesus Christ, who is at the center of everything we believe, and we come to participate in His life through the sacraments.
*
“Today the Church again proclaims their (Peter and Paul) faith. It is our faith, the Church’s unchanging faith in Jesus, the only Saviour of the world; in Christ, the Son of the living God, who died and rose for us and for all humanity.”*
You also disregarded the fact that the fulfillment of that prophecy cannot be empirically proven beyond doubt. A Muslim could claim that it refers to Mohamed, and that would be just as possible as the Christian claim that it refers to Jesus Christ. The point I was trying to make was that that is not how people generally become convinced that something is from God or not. Moses was undoubtedly the greatest prophet of ancient Israel. This is even attested by the Holy Book itself: