What are common things that both Orthodox, Roman Catholic and Protestants agree on ?
I have a little list.
Feel free to add:
1. The Holy Trinity
2. The Virgin Birth
3. The Divinity of The Lord Jesus Christ and The Holy Spirit.
4. The Old Testament Prophesies of Jesus in the Old Testament.
5. The Nicene Creed
Anything else ? I know there has to be more stuff that we agree on.
I think you need to define Protestants to really discuss this. Do you mean the Magisterial Reformers? Anabaptists? Pietists? Restorationists? Fundamentalists? Evangelicals? Emergent types? Etc.
I guess I mean Fundamentalist, Evangelical, And Anabaptists.
I know the Emergent Types are just plain Awful.
1. They agree on the persons, I think, but not their relationship. Does the Holy Spirit proceed from the Son or doesn't He?
2. I think most fundamentalists, Anabaptists and Evangelicals agree on the Virgin Birth as a fact. Not sure about all Evangelicals. What about the Rob Bell types? But what about its theological implications in terms of our redemption, Mary's preeminent role in choosing, etc? The Catholic position is characterized such that Mary couldn't refuse. We don't believe that.
3. I think that we all probably agree that Christ was divine. But the logical implication of this is that Mary is the Mother of God. The Council at Ephesus recognized this in 431. Do the groups you mentioned agree?
4. Probably yes, as far as they go. But our OT has more books than theirs and more prophesies. Read Sirach or the Wisdom of Solomon. Do they accept these prophesies?
5. I don't know if Anabaptists accept the Creed at all formally although they wouldn't disagree with its contents. Some fundamentalists and evangelicals would probably deny the authority of a council to adopt a Creed at all that is binding. And all have allowed "and the Son" to be improperly added to it.