Andrew knew that Jesus was the Messiah, the Christ.
But that isn’t what Peter said. Peter called Jesus the “Son of the living God.” It was that confession that prompted Jesus to give Peter the keys of the kingdom.
Does the distinction between “a” and “the” even exist in Aramaic and/or Greek? I doubt it.
You have been propagandized.
So Peter, instead of Jesus, is the chief corner stone of your church. Peter, and the prophets, say otherwise. Therefore your church’s interpretation fails the test of scriptural proofs.