"Perhaps about that time --- yes --- or at Pentecost. But the Roman Catholic Church was formed after Constantine took power in Rome."
Where in heaven's name did you get that idea? The "Roman Catholic Church", at least the Church caled that, didn't exist until after the Great Schism. Before that it was simply the one, holy, catholic and apostolic Church, or so the Fathers called it.
And the Fathers who called it that were right but also a little idealistic. There were several clues early on that the small "c" was destined to become the big "C" with "Roman" in front it. One was when the Bishop of Rome circa 380 AD began to refer to himself as the "Pontiff" and the other was Augustine's anointing of Rome as the City of God. The handwriting was on the wall ---