[Please note: The following are personal musings and not to be construed as *the* Orthodox understanding. If anything here contradicts the received teaching and way of life of the (Orthodox) Church, please correct me. As always: check with your priest or spiritual father.]
Criterion of Truth
One of the first and most important problems within ecumenism is by what means truth claims will be judged. For the simple fact of the matter is that irreconcilable contradictions in dogma among Christian groups are rife. Is baptism a sacrament and necessary for salvation, or is it merely a symbol without any salvific effect? Are the elements of the Lord's Supper really the Body and Blood of our Lord, or are they merely elements that have been assigned by Christians a certain metaphorical meaning? Is the Orthodox Church the one true visible Church Christ founded, or is the Roman Catholic Church that Church? Is Church unity necessarily visible, or is Church unity really only an invisible spiritual reality?
I've painted these in starker terms than is perhaps necessary, but not, I think, illegitimately. For while it is true that one can hold both that the bread and wine are the Body and Blood of the Lord and that the Church, through Christ's command, has, indeed, assigned metaphorical meaning to these elements, still one cannot hold that the elements have only metaphorical meaning and yet somehow are also metaphysically and really identified as Christ's Body and Blood. And while one may certainly affirm both that the Orthodox (or Catholic) Church is the one, true, visible Body of Christ and the invisible and spiritual reality of Church unity, still one cannot hold that Church unity is only or even primarily invisible and that any one particular Christian group is Christ's true Church. And so it goes.
But how does one otherwise adjudicate these fundamental and irresoluble contradictions? It can be done only by agreement on a single criterion or a definitive set of criteria. And it is just here that ecumenism fails, for of itself it cannot offer any such criterion.
What, after all, could it offer? Little else but either confusion or coercion. Either the Holy Spirit contradicts himself, or agreement must be enforced by political means. For it cannot be that the Holy Spirit has led one group of believers to one dogma and another group to another dogma which utterly contradicts the first. And if Church unity is invisible and spiritual, then the visible, fleshly unity among believers can be little more than politics and contractual arrangements. Either dogma matters or institutional conformity matters. But if dogma does not matter, what use institutional conformity? And how does one discriminate among dogma so as to know which is more important than another? What fellowship does one really have if groups cannot even agree on the place of baptism and the realities of the Lord's Supper? If we can't agree on how one becomes a Christian, nor on whether or not the Lord's Supper is the central act of God among his worshipping Body, then what, really, do we have? In the end, if all we have is respect and tolerance, what sort of unity is that? And what does it say about that sort of unity that we can have the exact same unity with non-Christian religions?
No, either we have an agreement on a single criterion, or we merely enforce political cohesion.
However, let us be clear here what is meant by “agreement on a single criterion.” It does not mean the making of a case for what seems best suited for such an endeavor. Rather, what is meant is the mutual coming to terms of the criterion that already exists. That is to say, the criterion is not something we produce or formulate ourselves. Rather it is something that is an objective fact whether or not we ourselves ever know it to be so. Ecumenism then has nothing of itself to offer. For it cannot agree on a criterion.
What I mean is this: For the Christian, the criterion of truth is Christ himself, who is “the way, the true, and the life” (John 14:6) and “in Whom are hid all the treasures of wisdom and knowledge” (Colossians 2:3). If Christ is the criterion, then what we say about Church unity must be the sort of unity he describes in John 17; i.e., that it is the same sort of unity shared between the Father and the Son, and between the Holy Trinity and us. So it is not a stretch to say that, what one says about the Church is what one says about Christ. If one has a deficient view of the Church, one will likely have a deficient view of Christ. Church heresies are tantamount to Christological heresies.
It is of the utmost importance, then, that what we say of Church unity conforms to what Christ has said and who He is. That is to say, while the union Jesus shares with the Father is ineffable, it is total. There are no gradations. Furthermore, if the unity shared among the disciples is a participation in that unity shared among the Holy Trinity, there is no division. Indeed, there is union of minds and wills. Furthermore, if Jesus is the Theandros, his Church is theanthropic. It is not some mere adoptionist or Eutychian institution. Like Christ, the Church is human and divine, no less one than the other. Like Christ, the union of the Church with her Lord is incarnate, and therefore, like Christ, whose divine and human natures are united without change, separation, division or confusion, the Church's unity is at once visible and invisible, at once one and plural. And if this union is living and dynamic, that is to say, if it is more than political, it cannot but have a dynamic connection through time and geography with the living Church in history and in heaven.
Clearly, then, what we have seen of ecumenism since its modern inception about a century ago is utterly deficient. It cannot instantiate, manifest, or even argue for the sort of unity Christ both prays for and makes possible. It does not have one mind, one way of life, or even the living connection with the past. The Church starts with both unity and plurality. Not one or the other. Just like the Holy Trinity.
[This is another in a handful of reflections I want to make on the matter of Church unity.