There’s a bit of hubbub in the theo-blogosphere about ecumenism and the unity of the church (e.g., at Inhabitatio Dei and An und fur sich). I haven’t given this a ton of thought because I think ecclesiology is boring, but, for what it’s worth, I see the unity of the church as having two aspects. First, it’s a gift; we are, through no merit of our own, reconciled with God through Christ in baptism–and, as a corollary, with each other. Second, this unity, which already exists, needs to be made visible. How do we do this? Through our works alongside other Christians of caring for the world and worshiping God. This doesn’t require all existing churches to merge into some kind of super-church. The church should not be divided along economic, racial, gender or other invidious lines; at the same time, there are differences that are legitimate and can be enriching. Unity doesn’t mean uniformity enforced in some top-down fashion.
As far as the implications for ecumenism go, in my view there’s already enough agreement for most major Christian bodies to be “in communion” with each other in the sense that we should be able to worship together, partake of the sacraments together, and work for the common good and well-being of the world together. Of course, not all Christians agree with this; some think more is required for “real” unity–something like institutional unity, or everyone being under the same ecclesiastical hierarchy, or agreement on fine points of doctrine. These aren’t issues that are going to go away in the near future. What I think we need to do is seek the greatest degree of unity possible while respecting the views of those brothers and sisters who feel that they need to keep their distance a bit. It may be that full visible unity is an eschatological concept.