21st Sunday in Ordinary Time
And I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it.
We do not hesitate to assert the Christ Jesus is the true rock upon which the Catholic Church is built – how could there be any other? And yet, we likewise affirm that Peter is the rock upon which Christ has built his Church; for the Greek is clear: “Peter” is petros while “rock” is petra, and the Aramaic would be clearer yet as the one word used for both was cepha.
It is as though Jesus said, “You are Rock (Petros/Cepha) and upon this rock (petra/cepha) [which is you], I will build my Church.” Christ is the rock and Peter is the rock, Christ is the foundation and Peter is the foundation. A man’s faith is founded upon Christ, only if it is founded upon Peter’s confession. Christ is the rock of the Church, only if the Church is set upon the rock of Peter’s profession of faith.
Let us consider why it is enough for the Pope to be infallible (i.e. unable to err in teaching), even if he is not impeccable (i.e. unable to sin).