In the introduction to his keynote address for the 2012 Craigville Colloquy, "Where is Mainline Protestantism Today?", William McKinney suggests one of the problems with discarding the term, "mainline," namely there is no good replacement for it. He observes,
“Mainline” is one of several labels (among them: “mainstream,” “ecumenical,” “modernist,” “public,” “established,” “old-line,” “progressive” and “liberal”) used to refer to Protestant churches and sensibilities whose experience in America dates to the early years of European immigration. Each of these terms is theologically and sociologically imprecise due in part to the fact that in the US setting today even the term “Protestant” is problematic. Sociologically and theologically, the term “Protestant” has little meaning beyond suggesting what one is not: not Roman Catholic, not Jewish, not Muslim, not a “religious none.”And "mainline" adds to that list of things we are not namely, not evangelical, not fundamentalist, and not Mormon—among others. The term, "mainline," is widely recognized and widely accepted. In the face of the fact that no other term is really any better, the effort involved in trying to replace it with something else that is no better seems problematic.
More to the point still, in some real senses and perhaps sadly we still are mainline churches. We are mostly white, stagnant, and still behaving institutionally as if we are the establishment churches of our communities long after we have ceased to be such. There is, of course, much more to being mainline today than these characteristics, but by the same token the term mainline still resonates with our core identity. If names matter and if we should call each card by its right name, then we remain mainline churches.
Rather than change the label, what we are learning increasingly is that we need to substantially transform the contents of the package. In Britain, Anglicans and others call the process of discovering new ways to be the church, "fresh expressions." In the PC(USA), a similar movement is called, "1001 Worshipping Communities." The goal in both cases is to establish new-fangled churches that are viable faith communities within themselves and better able to share their faith with others.
In short, what we really need to do is to think about what it means to be mainline in new ways—own the label and really make it our own by redefining it. Amen.