Prior to Nicea there were many differences between the churches, doctrines of different churches were wildly different in some cases. When The Church, or Constantine said “This is not the approved doctrine” many bishops went away facing excommunication because they disagreed. Constantine relented and didn't force the new doctrines on all, but later, only about 50 years later it became Church law and refusal to submit to it meant excommunication and even in many cases death.
So, many previously approved scriptures were burned, they didn't agree with Nicea. Many good bishops were lost. Many doctrines that were considered normal were banned.
Many can say that some sect, like the Mormons, or the Baptists or any group are wrong but there is no leader to make it so except for the Pope. Think about it there is no authority on earth in Christianity except for the Bishop of Rome. Yes I know the Mormons have a Prophet, that too is an authority, but who else claims such authority? Nobody. There are boards, and other groups in nearly every church but who can decide this or that doctrine correct or wrong? The Mormons have somebody and the Catholics have somebody. You may not agree with those somebodies but at least they have somebody willing to say yea or nay!
Prior to Nicea there were many differences between the churches, doctrines of different churches were wildly different in some cases. When The Church, or Constantine said This is not the approved doctrine many bishops went away facing excommunication because they disagreed. Constantine relented and didn't force the new doctrines on all, but later, only about 50 years later it became Church law and refusal to submit to it meant excommunication and even in many cases death.
So, many previously approved scriptures were burned, they didn't agree with Nicea. Many good bishops were lost. Many doctrines that were considered normal were banned.
....aaaand the "Great Apostasy" of Mormonism has entered the thread.
Well here is another...The Hidden Mahdi, the 12th Imam. The Shia say he will rule over the other two guys you mentioned and they will see their errant ways and serve him as Allah's rep on earth.
All three have something in common. They all (when the Mahdi allegedly appears he will) say 'they' are the main authority. They also have something in common. They are mere mortals like the rest of us. Complete failure there.
Who told you that??? God, or your pope???