Matt Black said:
That's one of the big 'what ifs' of church history. With respect, it's kind of approaching the question from the wrong end: I would prefer to surmise that, had there been no schism in 1054 and East and West continued to meet, when necessary, for additional Ecumenical Councils, then the Reformation would not have been necessary and hence Trent would never have happened in the first place.
Yes, I do believe that, with perhaps the exception of the "no less than Scripture" of +Kallistos Ware. I don't see that as raising any 'cognitive dissonance' with my being Anglican; after all, the Book of Common Prayer has the Creed thrashed out at Nicaea I and Constantinople I in plain as day. [ETA, from Pedants' Corner - * Not quite correct: there were Lutheran observers present at the first session of Trent, much as there were non-Catholic observers at Vatican II. But I agree that in both cases neither had any say in the proceedings or the decisions reached]
I know that we are on "shaky ground" with what-if situations, but my personal opinion is that the Reformation would still have been needed whether or not the schism of 1054 had occurred. I readily admit to being no expert on Eastern Orthodoxy, but from what I have read, it is very similar to Roman Catholicism, and greatly different to the churches of the Reformation. For example:
Both believe in prayers to and for the dead.
Both have the bible plus tradition as their authority.
Both have seven "sacraments", including confession to a human "priest".
Both have a human priesthood, distinct from the priesthood of all believers.
Both believe that baptism is necessary to salvation.
Both practise the veneration of statues and icons.
Both see value in monasticism.
Both believe in transubstantiation.
Regarding "the Creed thrashed out at Nicaea I and Constantinople", yes, it is in the Book of Common Prayer, and in my opinion it is perfectly acceptable to evangelical Christians today. But of course, it makes no mention of the sort of things I listed above (bible plus tradition, seven sacraments, confession to a human priest, etc.) Here it is as in the 1662 BCP (Matt probably knows this, but to avoid confusion, "very" means "true", and "Catholick" there means "universal", not Roman Catholic"):
I BELIEVE in one God the Father Almighty, Maker of heaven and earth, And of all things visible and invisible:
And in one Lord Jesus Christ, the only-begotten son of God, Begotten of his Father before all worlds, God of God, Light of Light, Very God of very God, Begotten, not made, Being of one substance with the Father, By whom all things were made: Who for us men, and for our salvation came down from heaven, And was incarnate by the Holy Ghost of the Virgin Mary, And was made man, And was crucified also for us under Pontius Pilate. He suffered and was buried, And the third day he rose again according to the Scriptures, And ascended into heaven, And sitteth on the right hand of the Father. And he shall come again with glory to judge both the quick and the dead: Whose kingdom shall have no end.
And I believe in the Holy Ghost, The Lord and giver of life, Who proceedeth from the Father and the Son, Who with the Father and the Son together is worshipped and glorified, Who spake by the Prophets. And I believe one Catholick and Apostolick Church. I acknowledge one Baptism for the remission of sins. And I look for the Resurrection of the dead, And the life of the world to come. Amen.
If that was all Roman Catholicism and Eastern Orthodoxy believed, then perhaps there might have been no need for the Reformation.