You focus too much on man. Man will always let you down because they are mere men.
Well, although we're nowhere near a Godlike stance, I don't think you're giving humans the credit we deserve. While it's obvious that there are an abundance of people who seem to be making a waste of their lives, or just totally failing at it, we have done some amazing things. We've captured lightning in a bottle with the lightbulb....we can literally move mountains, or destroy an entire city with the push of a button...anything you could ever want to know or see, is possible with just a few keystrokes and click of the mouse...things that would appear simply as mere magic to our 1000 year old ancestors.
Yet most people choose to take such a useful and progressive tool such as the internet, and abuse it for nothing more than mild mind dumbing youtube videos and the notorious social networks...so I could see why you might feel the way you do, and its true in a "shade of grey" sense. Turn on the tv on any given channel, and there's bound to be someone doing something stupid to try and get their 5 minutes of fame...rediculous. All the while they could use the internet for more useful things, like attaining knowledge.
But it also wasn't any suprise seeing those study results. I lived in the bible belt for the most part of my life, and I'll say that really, only the older generation churchgoers really knew their way around the book....teens to middle aged adults, a fraction of the part.
This isn't the result of the clergymen though. It's a combination of both advancement (we're getting smarter, starting to open our eyes a bit wider, though this still is only a small portion of the general population) but also a nasty sideffect of the coming of age with new technology (the internet being the key component). The fabrics of family values are coming apart at the seams, with less and less dinners at the table and interface, and more texting/myspacing with friends and staying on the go. Back 40-50 years ago, for most people, it was work, family, sleep, church on sundays.
Theology has worked well through the ages, and to a small degree I think it lays out a decent (but vague) guideline on how to generally be a good person. But the fact that we're really starting to dig for the answers more and more, let's me know were still progressing as a species. If there's one thing I have faith in, it's that we'll be able to come to a conclusive answer sometime, whichever it may be.