Theories of the Apocolypse and Trib/144 could very well be the "scribbling of some raving looney." There's dispute about the Apocolypse, it's authorship and authenticity within the RC Church.
Keep in mind, it doesn't matter that the RC Church, who compiled, authorized and promulgated the New Testament, recognizes certain shortcomings. According to the fundamentalist mindset, anything less than complete, unconditional, unquestioning acceptance of biblical text is pure, unadulterated heresy. The NT must be accepted literally, without regard to broader context, authenticity, or history. Anything less is apostasy, and gravely sinful.
Imagine, all those bumperstickers could be a big waste of sticky paper? LaHaye's fictional series, "Left Behind," is fueling rapture mania. Mr. LaHaye, a prominent theocrat, has made a fortune selling the Rapture to a god-fearing public.
Mormons only accept NT teachings that can be reasonably authenticated, or validated by another source. Mormons aren't saved either.