If the average papist could read, Rome would probably collapse in about a day:
Matthew 16:17–18 (ESV):
»And Jesus answered him, “Blessed are you, Simon Bar-Jonah! For flesh and blood has not revealed this to you, but my Father who is in heaven. And I tell you, you are Peter, and on this rock I will build my church, and the gates of hell shall not prevail against it.”«
“This” appears twice in the Christ’s reply to Peter (who had just confessed that Jesus is, indeed, “the Christ, the Son of the living God”); it references the same thing in both cases. In the Greek, the first instance is implied (this is natural in the Greek, but unnatural in English) and the second is explicit. A Koine Greek reader or hearer (of sufficient intelligence, anyway) would have immediately recognized the second ‘this’ (ουτος) as referring to the same thing as the (implied) first ‘this’: Peter’s confession.
The Rock upon which the Church is founded is Christ, and Peter’s confession of Christ is metonymically or synecdochically identical to Christ Himself. There are dozens of ways in which it can be clearly demonstrated from the Scriptures that Peter is not, personally, the Rock upon which the Church is founded. Here are just a few:
1. Christ calls the Apostles (plural) and the Prophets the foundation (Ephesians 2:20).
2. It is clearly stated (in a number of places, e.g., 1 Corinthians 3:11) that Christ Himself is, indeed, the Rock.
3. Peter is not even the Apostle to the non-Jewish nations, for that role was bestowed upon Paul (Romans 11:13).
Peter himself, undoubtedly, understood what Christ was saying, as he never called himself the Rock upon which the Church is founded (and also he probably noticed that “rock” [πετρα] is feminine and Peter was, well, not); in fact, Peter himself clearly affirms that Christ is the cornerstone and rock of offense (1 Peter 2).
And there is also the fact that Scripture itself contains the narrative of the first council ever called (Acts 15), and Peter did not preside; rather, it is James, the brother of Christ, who renders the judgement, and the decision is sent in the name of the church, not Peter.
Peter is not unimportant, certainly, but he is not the Rock upon which the Church is founded, and he would probably punch you in the mouth for saying so.