Mega-mania?

An article in Harper's magazine offers a disturbing look at what it calls "America's Most Powerful Megachurch". It suggests a true alternative universe in which demons roam, looking for bodies to inhabit:

The demons are cold, they need bodies, they long to come inside. People let them in in two different ways. One is to be sinned against..... The other is to be in the wrong place at the wrong time. You could walk by sin—a murder, a homosexual act—and a demon will leap onto your bones. Cities, therefore, are especially dangerous.

So apparently are ethnic restuarants, women who work outside the home and anybody who doesn't look like you, think like you, and own a fake-white-picket-fence suburban cookie-cutter house like you. It's conformity as the ultimate expression of religious conviction.

These people don't need a logical argument in favor of universal health care; they need therapy. Is religious fundamentalism nothing more than a mega-construct for denial and the avoidance of reality on a mass scale? Is it, in effect, a form of mental illness?

There is an interesting, though passing, mention of this question in Jon Krakauer's Under the Banner of Heaven. What is the difference between faith (that is "faith", as in "faith-based") and madness? I suspect there is one, but reading articles like this one (above) makes me wonder if some true believers haven't crossed over the line.