Presbyterian Church (U.S.A.) Gives Final Approval for Same-Sex Marriage

[Rockefeller GOP]

As someone who grew up in the Methodist church, I'm pretty certain that the Methodists will never come around on this issue. In fact, most of the people I went to church with growing up (and yes, I'm an atheist nowadays) think that same-sex marriage will cause America to disappear off the face of the earth.

Guessing you didn't grow up in the Methodist Church of 2015, though.  I mean it was 5 short years ago that no one influential in either party supported gay marriage.

[Rockefeller GOP]

but more than 30% of the members of the UMC are not from the US, with most of them coming from Africa or the Phillippines.  And that proportion keeps growing and growing.

This sort of change and it's not unique to that church or even to the USA in terms of western Christianity is a potential breaker on any moves towards greater LGBT inclusiveness. The global church, outside of western nations or even western inclined church hierarchy is on the whole taking a more regressive stance on those matters, when a decade ago it wasn't even an item on any agenda. If there is continual foot dragging then many USA/European churches might not actually move towards the secular 'benchmark' on LGBT issues.

The big issue in the west is that particularly amongst young people, LGBT rights it now no longer about agreeing or disagreeing, but it's becoming a red line issue. I am greatly encouraged by a lot of young people and young Christians taking the position that it's almost incompatible to be a part of the human family and oppose LGBT people for who they are. It's the modern day equivalent of supporting racial theory or in built male superiority.

Choosing LGBT issues from the 80's to now as the hill to die on simply for short term benefit probably won't pay off in the long run, at least amongst western churches.

The Christian Right will find someone new to despise, they always do.  Now that non-religiouses are upwards of 1/3 of millennials I suspect that the "atheist/secular" agenda which has only been tangentially their target will start to feel their full "wrath".   

I mean... they've gone through race, political affiliation, sexuality... what's left? 

I don't think it's fair to tie deeply religious people with race-related "wrath."  I mean, with both slavery and the civil rights movement, some of the most deeply religious leaders and congregations were the first ones to get the ball rolling toward equality and more enlightened race relations..