I never really got the impression that they were viewed as "enemies" so much as subhuman labor, like a tilling-horse or other beasts of burden in those days.

People get serious about religion because often it's their belief in what occurs in the eternity after this comparatively short life, I can understand why they're so serious. What I don't understand is why most won't ever be content to "live and let live", by letting others live the way they want/believe, especially when it doesn't encroach on their beliefs.