As a Protestant who is both ecumenically minded and who takes ecumenism to be seeking to be truly catholic (I do understand that not all interpret ecumenism in this way), The Claims of Roman Catholicism and Eastern Orthodoxy are two horns of a dilemma upon which I find myself gored. Part of this problem is that I know that I as a Protestant and a Lutheran Pietist have a residual grudge with the Roman pontiff. I know that part of my attraction to Eastern Orthodoxy is that it shares my Protestant ambivalence (Remember I am ecumenically minded so the old polemics against the Pope seem a bit overdone ) or even polemic against current Papal claims. Yet, at the same time I also have to admit that there is/was something to the "seat of Peter" and I certainly can't deny that until the Great Schism that the Church held the Bishop of Rome in high esteem and that the Bishop of Rome was seen as a defender of the faith and an important possibly even essential one. But I still can't get away from what seems to be a great gulf between ancient and early medieval Papal "primacy" and what emerged especially after the schism (though evidence of this direction can be found a century or two prior.
The other problem is that both East and West continued to develop doctrinally at times in ways that at least on surface seem incompatible even beyond the question of the Papacy.
So in doing some surfing I happened upon a few months old post at the Pontificator's explaining why his interest as an Episcopalian in Orthodoxy did not lead to his becoming Orthodox and why he instead has become Roman Catholic. The June 9th post is interesting and I recommend a read of it, and a perusal of its 421 comments, some very interesting responces to the post from both sides of the fence and from some on neither side of that fence.
I find the post interesting on many levels. First it reflects some of my own struggles though with the obvious differing conclusions (though who knows). Second while I recognize his struggle I find both his appeal to mystery and his attempt to account for what he claims to be inexplicable unconvincing. (I have e-mialed him to let him know I am commenting on this old post of his.) primarily because his accounting is simply articulating what is the problem of being outside these two churches: that there is no way to judge their differing claims to be the One True Church. From the outside I can see that there is historical precedence for a type of Papal "primacy" but it is far from clear based on that same historicity that what Roman Catholicism currently claims for the Pope is in fact the same thing Pope's and the Church have always claimed for the good Bishop of Rome. Yet, Orthodoxy doesn't seem to do too well in addressing where Petrine minsitry is continued in Orthodoxy, nor how to account for its loss at the schism and still have the one Church. (now it is possible that I have not read widely enough to find such explications.) Frankly, as a Protestant Orthodoxy's claims are more palatable than Romes. Even a scholar like Carl Braaten who is Lutheran and sees some role for the Bishop of Rome isn't really entirely comfortable with current assertions made by Roman Catholicism about the Popes role and, to put it bluntly, power. So, where I am lead in terms of Rome and Orthodoxy is a both/and and not a either/or, (or niether/nor which seems to be some of my Protestant siblings responce to this dilemma). But really neither Rome nor Orthodoxy even in their most irenic poses allows for such a proposition because it means that in some sense both are in schism from each other that neither can claim the high ground. This of course causes theological problems on the level of ecclesiology for both, since the church is one not simply in some abstract sense but in a concrete and historic sense. This claim makes sense to me abstractly, but seems contradicted by the history that stands plainly before us.
Also, the discussion that followed was interesting, very much like watching tennis though. But what this leaves me with is the impression of a competition going on between Rome and Orthodoxy, each trying to convince the other (and any observers) through there astute use of Scripture, Patristics and rational argument who really deserves the trophy of the Una Sancta. I do not mean to impune anyones intentions here because at least in the comments left on this post it is clear that most if not all are deeply respectful of each other and are in fact convinced of the truth of their position. What I want to say to both sides of these arguments which have been in one form or another taking place for well over a thousand years (since the Great Schism it can be argued began a century or two before the split officially occurred), is do you really think your claim to Papal Primacy and your denial of it in it current articulation really convinces anyone that you are followers of Jesus Christ and members of his Body? Frankly given our track record for the past thousand years, I can sympathize and empathize with those friends and aqcuaintances of mine who look at these and other arguments that seem to consume us as Christians and find no evidence of Christ or His Body (whoever can actually claim to be that, I do not mean to argue here that all of us who claim to be Christians are in fact all members of the Body of Christ). I have to admit that to some degree when I see these sorts of almost pendantic debates I am frankly embarassed for us Christians. This is not because I think that some how dogma is unimportant or that these questions are inconsequential. However I love Christ I love the Church, I want people to find Christ and to find their home in the Church, but much of the wrangling about this or that seems to lift up things like the Bishop or Rome or Not having the Bishop of Rome as the cornerstone of the Church. When in the end the Pope is nothing, the Patriarch of Constantinople is nothing, the Heirarchy of the Church is nothing, the Councils of the Church are nothing unless they show forth the Gospel of Jesus Christ and lead people not to follow the Bishop of Rome or the Councils but Christ the Head of the Church. It seems that at least in the debates I have followed that this is often forgotten.
In the end this I know: it isn't these debates that keep open for me the question of where the Una Sacta is, it is in fact the love of individual Roman Catholics and Orthodox who accept my struggle and say very lovingly "...But do you see where Protestantism is deficient here", and then say "May God bless you on your Journey." As my wife has said of one of our Orthodox friends, it is those who smell of Jesus both Orthodox and Roman Catholic who keep me from being complacently Protestant. All your arguments in the end are stale, it is when you present Christ that I am convinced but then there is always this thousand year old dispute, which sends me into a theological tail spin.
So for now I will co-pastor a tiny ecumenical congregation, write icons and pray. Lord, have mercy.