You want to know how you can tell organized religion is in big trouble? It's easy. Look around. No youth movement.
When I was a kid there were literally hundreds of groups around the country, big groups of religious fanatics, made up of nothing but kids in their teens and twenties. Kids from all walks of life and different political persuasions. Calvary Chapel was in my neighborhood. They'd pack thousands into a big tent several times a week and have huge ocean baptisms at the beach. Tony and Susan Alamo's followers traveled around in fleets of buses Shanghaiing prospects for cult indoctrination. There were Obnoxious Moonies all over the place. There were very large religious gatherings everywhere you went in those days. In Parks. Colleges and Universities. The beach. The desert. All nothing but kids. The kids believed. I mean really believed.
There were a lot of non Christian groups. Hari Krishnas. Rajneeshis. Transcendental Meditators. Scientologists. A bunch more. They were even crazier than the Christians. Most of these pagans eventually came back to Christianity and became the most crazily devout, fundamentalist, old fart Christians today.
The point is, fanatical religion is a lifelong pursuit and just growing up with it in the family isn't nearly good enough to secure the soul. You have to catch the fire while you're young, even if you flicker on and off during your salad years and don't come back to the faith full force until middle age.
The reason there is such a strong constituency of religious nuts between the ages of fifty and sixty five out there now, is because they were always out there, just as crazy. I can look back at my high school class and count them off, friends I grew up with and lost to religion between the ages of sixteen and twenty two. Most of them never came back. They'd come around, share a toke and try to bring you into the fold but if you rejected the Lord, it was like you were dead to them.
I'm not saying the Lord doesn't still bring in the occasional youthful sheaf but it's nothing like it was, not even close and in twenty or thirty years it's going to make a huge difference in the Christian community. Christianity has a big problem coming up.