I think you misunderstand. Those who swore an oath to defend that document don't view it as a "holy relic" either - but rather as the affirmation of natural human rights. Ones which no government can take away.
Likewise, the "Founding Fathers" were simply the intelligent or leading men of the day who when constructing our government argued about human nature, disagreed a lot, and eventually settled on a framework that has stood the test of time longer than any other government of its kind.
Speaking of human nature, I think you are wrong, but only partially so. While there are certainly good and rational people, there are also certainly people who are irrational and/or "evil" as you put it. Speak to a beat cop from East St Louis, Chicago, or any other major metro area with a lot of crime sometime and you will get a perspective that will likely shake your worldview. Assuming you're a rational person, of course.