What a man truly believes is more accurately reflected in how she/he behaves than in what he/she professes to believe.
One of my favorite religious phrases, and one that I feel is extremely revealing, is the term "justification through faith". I believe it, so it must be true; if true, it must be right. Bin Laden, the Taliban, the Inquisition, and all of their unholy ilk are just a bunch of power seeking, self-aggrandizing murderers. No God worthy of the name would accept or forgive such perverse behavior, regardless of their piety or their belief.
Inevitably, someone writes a book and, regardless of what a Good Book it is, someone else decides to hit people over the head with it. I'm having none of it.