If I may put a finer point on it, the question is this: Is there a normative (biblical?) ecclesiology that is timeless, to which every congregation must aspire? Or is ecclesiology necessarily shaped by the culture that inevitably envelops every congregation?
I unequivocally say no to the former and yes the latter.
I am most interested, as I wrote above, in theologies that are grounded. My criticism of Jürgen Moltmann is that he is too idealistic, too naïve—and he’s exponentially more grounded than Milbank, Hauerwas, and the other ecclesiologists on the scene today. To develop an ideal ecclesiology—an image of the perfect, eschatological church—doesn’t do anybody any good because it’s pure hypothesis. It merely establishes a aspiration of which every congregation in the real world will fall short.
Every congregation is dripping with culture. It comes into the sanctuary in the clothes that congregants wear, in the music they were listening to in their cars on the way to church, and on their phones as they check Facebook during the introit. A realistic ecclesiology will acknowledge culture; it will recognize that parishioners talk about their experience of the numinous using cultural idioms, not second-order theological discourse.