Even their holy book is stupid. But of course having it arranged that way makes it difficult to understand, or even follow. Thus the need for an Imam or Mullah to tell you what it means. Far too many seem to think it says "Kill the Infidels", which of course it does in a few places, but so does the Old Testament. But you don't see many Rabbis emphasizing that message these days (or anytime, at least since well before the diaspora)
I can't be bothered to look it up, but, as I recall, the koran starts whining about infidels and the need to punish them on the sixth line of the very first book. It skips the silly origins of the universe stuff that the Bible at least tries to get right and goes straight to the infidels-suck-and-we're-gonna-kill-'em stuff.