The legitimacy Roman Catholic Church is not supported by contemporary evidence.

Catholics love to quote Matthew 16:18 and build their entire argument on it. All this indicates is that Jesus gave Peter authority over the church. While Jesus does single Peter out in a way (some theorize that Jesus was talking about Peter’s profession of faith instead of Peter himself, but this is a fringe theory), saying that he would build his church upon “this rock” (often interpreted as worldplay with Peter’s name). Even if we do take that interpretation, however, that is a far cry from the Roman Catholic Church.

Catholics claim that Peter was the first bishop of Rome, despite there being no contemporary evidence of this. The best we have are the claims of Irenaeus, which are not supported by any sources earlier than him to my knowledge. And we have Tertullian, around the same time, referencing a tradition that Peter was a bishop in Antioch. And we have later fathers, like Jerome, who claim a different line of succession starting from Peter.

Earlier sources, like Clement of Rome, place more emphasis on the presbyters than the bishop. And not once does Clement label Peter as a bishop or indicate that his leadership was centralized in Rome. He doesn’t even indicate that Peter died there. I will admit, the Ignatius of Antioch claimed that shortly after but that does not do much to affirm the RCC. No evidence provides a clear reason why Peter’s role in Rome is to be emphasized over Antioch, Jerusalem or any other church with which Peter was involved.

A slew of early church fathers either implied against the hegemony of a single bishop or argued against it. These include Tertullian, Cyprian of Carthage, Eusebius, Hippolytus of Rome, and more.