The Apostle Paul was fighting against false doctrine from the beginning of his ministry. It's why he wrote his letters. The bishops continued the false doctrines and eventually, there were no replacements for the Apostles who died. When John died, then the word of God could no longer be sent via messenger (Prophet-Apostle) and the world was in apostasy except for the Americas. But, another 100 years after than, the people in the Americas began to be prideful and started rejecting the Prophets. By 421 AD, the heavens were closed to the Americas and the world was in a age of darkness.
The good news is, there were 4 Apostles who did not die and are still in a translated state of being today. John and the 3 Nephite Apostles asked to tarry until Jesus comes again. It could have been John that Constantine saw and was told to compile the writings of the Apostles into a new testament of Christ to be joined with the old testament as the stick of Judah. They are to keep a spark alive until the restoration of Christ's Church was restored in 1830. They continue to help bring forth the fulfillment of prophecy like the restoration of the state of Israel for the Jews. And, the Jews did not start the 1948 War.
Myths & Facts - The War of 1948
The bad news for you is that since the Catholic Church was not the true Church of Jesus Christ, neither would any other church that formed from that Church. The dead tree cannot produce live fruit. Thus, the restoration of the Church by Jesus Christ was needed to open the heavens back up.