Wherefore if we, by the revelation of our Father who is in heaven, shall confess that Jesus Christ is the Son of God, having also our conversation in heaven, to us also shall be said, “Thou art Peter;” for every one is a Rock who is an imitator of Christ. But against whomsoever the gates of hell prevail, he is neither to be called a rock upon which Christ builds His Church; neither a Church, or part of the Church, which Christ builds upon a rock.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).