"provided their mullah or archbishop or 8 armed elephant doesn't tell them to blow up skyscrapers or burn unbelievers to death or start a crusade?"

That his whole point isn't it? People do those things. And they are given legitimacy to an extent by the large numbers of other "believers" who may not act out themselves, but whose own "faith" supports the notion we live in a universe where reality is subject to the whims of invisible Gods, and Devils, and demons in conflict over our "souls" and all of that kind of hocus pocus that these unstable people feed off of.