There were many local churches, many of them named in the books of the Bible that was assembled, and they were one holy catholic apostolic church. There has been a continual historical testimony of the Messiah from the Apostles to this day.
I agree there were many churches. But no pope. No Mary worship. No priests offering sacrifices, no indulgences, no infant baptism, no praying to dead saints, no “saints” in the rcc view, etc, etc.
Then it should be EASY for you to explain the ERROR in the 'church' found in Revelation.