Reading again about the atrocities of the medieval church and religious wars and acts of terrorism since, it occurs to me that we ought to have a very simple rule about religious power.
Any religious group is allowed to exercise as much power as they wish - power to damn or kill abortionists, gays, atheists, Anabaptists, Muslims, politicians, people who walk funny or people who reject Joseph Smith. Seriously. Of course, given that it is religious belief we're talking about, it seems only appropriate that there be one catch to this: exercise all the power they want as long as it is supernatural power. If you can direct the wrath of God, you ought to be taken seriously. And further, you don't even need a political process.