Why do bible fundamentalists act like being against them means being against Christianity?

when someone challenges their beliefs, they accuse that someone of being against Christianity. aren't they aware that they are not the only Christians existing, and that there are many other Christians out there that don't belong in their little club?
Update: Hope, not only the so-called bible fundamentalists believe the bible. other Christians outside your little club do, too.
Update 2: don't "shoot" me just because I noticed what's going on.
15 answers 15