A discussion I had with a teenager a couple of years ago illustrated this mindset well. After he espoused some relativistic sentiments, I pointed out that if everything is relative, he couldnt rightly say that racism or sexism was wrong. He actually agreed, saying (Im paraphrasing), It sometimes scares me that theres no Truth, and sometimes I wish there was, but thats just the way it is. He ended the conversation shortly thereafter, before I could marshal further arguments. And the real tragedy is that this wasnt done out of anger but ennui. But how culpable was he for his indifference? He had been taught that there are no treasures to be found, no answers only preferences. Thus, searching for them made no more sense than laboring long and hard to discover whether chocolate, vanilla, or strawberry is the best flavor. A quick taste tells you all you need to know because its whatever works for you, man. So from his relativistic perspective, his intellectual incuriosity was entirely logical.
The following is a non partisan University study. http://hirr.hartsem.edu/research/fastfacts/fast_facts.html
It appears liberal churches have lost the most, but there is still an overall increase.