I think it's less ingrained in modern culture than it seems. Much of the mainstream (and fundamentalism is not mainstream, but, rather, extreme and fringe) religious participation is social based more than it's faith based, with lots of lip-service and not much underlying conviction. It's trending older, poorer and rural with fewer and fewer people under 35 believing than at any time in our history. In other Western nations religions have drastically reduced numbers over the last 50 years, and ever so slowly the US follows. One very telling statistic is that of vocations/callings, as seminaries experience 'graying' as their students get older (finding fewer and fewer young people willing to attend), and in the case of the Catholic Church you see that they don't even have enough priests to put one in every parish (and those they do have are increasingly foreign born), and Catholic Schools which once (like when I went to them) were overwhelmingly run by nuns and other clergy, now are pretty much lay run.