Albion,
IMO, the liberalism that ravaged Christianity in the 18th-19th Century was born of the Enligthenment and Rationalism - and fundamentally was driven by doubt, skepticism and a "prove it" mentality. Some of these WANTED to hang on to something (perhaps in their hearts being Christian) but it was a case of pealing an onion... there often was little left (and no reason to stop with that).
I think in the 20th (and now continuing into the 21st) the issue is not liberalism but relativism.... an attitude that truth is unknowable and irrelevant (and besides, it divides and makes people nasty)... It's all what you FEEL and EXPERIENCE and a bit of pragmatism as to whether it "helps" you. Denominationalism has been enormously weakened - not because progress was made toward truth because the whole issue of truth is increasingly abandoned. Lutherans often had no idea of what makes Lutheranism distinctive or any real commitment to that (in spite of what they said at their Confirmation). Increasingly, I fear, many denominations are distancing themselves from their own theology..... not in a spirit of truth or even humility but because their hero is Mr. Rodgers, they like holding hands and singing "Kumbyah" and because in their hearts, Truth doesn't exist.... and doesn't matter..... FEELINGS matter.
My brother attends a HUGE mega non-denom (I'm sure you've heard of it). VERY popular! But it believes pretty much nothing. My own brother admits there is no theology.... beyond Jesus is good for you and can make your life better. LOTS of sermons on how to improve your marriage.... how to have obedient teenagers..... how to be economically successful..... lots of stuff about getting through tough times.... all conveyed primarily through LOUD music that would put any rock concert to shame and presented by a rock star pastor in jeans and an Aloha shirt. Communion is never shared because "it's impossible to do in our ventues" and Baptism is never done because "people have different ideas about it" - although one can make an appointment and someone will baptize you anyway you want for any reason you want. THIS is the face of post-modern Christianity. And it's the greatest threat to Christianity since Gnosticism.
- Josiah