I was editing the 101st episode of Homebrewed Christianity, a conversation primarily between Paul Capetz and John Cobb. It was a fantastic theological dialogue … and then then subject turned toward practical matters.
What happened to the Mainline church? Why is it in such decline?
It turns out the answer, according to Cobb, is both complex and not completely absent of theology.
He details three major shifts that spelled out a recipe for disaster:
The first shift was an acculturation. In post World War 2 America, there was a boom in church attendance as it played a vital role both socially and in the family. In a twist of fate, the Mainline churches (and social gospel) were successful – maybe too successful. The church got comfortable. The church liked its forms – especially liturgy. The church was satisfied with the direction and changes of society. Cobb doesn’t use the word complacency but self-satisfaction about success can become paralyzing in future discussions.
The second shift was a diminishing of the importance of theology. It was the ecumenical mentality and apathetic attitude toward theological difference that somehow resulted in a mentality that it doesn’t really matter so much what you believe about this specific or that. At some point one has to think that this casualness about theology is not simply laziness but an abdication of core responsibilities.
The third shift came in the 70’s when the Liberation Theologies showed up and “they knew exactly what they believed and were not afraid to say so.” The Mainline was impotent and irrelevant by comparison. (my words, not Cobb’s)
When you put these three together, you see a perfect storm: loss of intensity due to acculturation, loss of identity due to theological abandonment, and loss of relevance (potency) due to shifting contexts. 
The first shift gets a lot of attention. Philip Clayton has talked about the ‘collapse narrative’. Dianna Butler Bass has done great work on both dying forms of liturgy and efforts of revitalization. Brian McLaren had some powerful and innovative thoughts on the subject [toward the bottom of the link]. The overwhelming consensus seems to be that purely theological explanations are too simplistic and miss the overarching interrelatedness to the shift in the surrounding culture. I have always been told that it is because they “sold out” to the culture and “compromised the gospel”. I never bought that – there was too much good coming out of churches like that and I had met too many people sincerely committed to Christ’s work.
It is the second shift that really piques my interest. Cobb doesn’t specifically talk about hermeneutics, but I have been bewildered at, what seems to me, a willingness of Liberal thought to saw at the Biblical limbs on the tree side of the limb that they stand on. This is self-sabotage! You can not undercut the very thing that your existence stands on without weakening your ability to stand at all.
The third shift is potentially the one with the greatest consequences… and the most potential for turn around. It is the church’s willingness to engage its surrounding culture and embrace the task of forging an authentic expression of the gospel in our local context that gives us relevance. This can be done with a progressive reading of the Bible and a Liberal, generous stance – no matter what our weekend gatherings look like.
The old wooden beams in the sanctuary may not make it through this shift. But I have great confidence that both the work of the church and the people of Christ’s spirit will endure in multiple streams. A progressive reading and expression of the gospel is a message of great hope to many in our emerging, decentralized, inter-connected culture and world. The forms and structures may need to change, but the historic impulse can be cultivated and harnessed.
Cobb and Capetz have me thinking about this stuff from a new angle.