As I see it, a narrative-historical theology is bound to recognize that the collapse of western Christendom is a profoundly significant event in the story of the historical people of God—as significant as the exodus, the exile, Pentecost, the destruction of Jerusalem, the conversion of the empire, the Great Schism between East and West, or the Reformation. The story does not begin with Jesus and it does not stop with Jesus. Our theology, therefore, is unavoidably post-Christendom and should be aware of the fact: the context is not incidental.
For this reason I think that the Anabaptists, who have embraced the current marginalization of the church more enthusiastically than most, are worth listening closely to. Closely, but not uncritically. Anabaptists have been so quick to embrace the post-Christendom reality of the church because they have always been resolutely opposed to the cosy collusion between church and political power that began with Constantine. But this entrenched antipathy, like any ideological bias, can lead to distortions.