"Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blindfolded fear." -- Thomas Jefferson
This is one of my favorite Jefferson quotes, for quite a few reasons. Since the dawn of our church, blind faith has been the byword. Why? Because a person afraid to question is a frightened, easily manipulated slave. A thinking person is not so easily bullied and made to do what you would have them do, thus it is not in the interests of churchmen who would control to have a thinking flock. Ignorant, unthinking sheep are certainly easier to fleece and herd wheresoever you would direct them.
And a believer who doesn't think, who doesn't stop and ask, “So what if my faith tells me to do it? Is it right?” That's a dangerous person. That's the Muslim who puts a bullet in a little girl's head, because she wants an education. That's the Christian priest who tortures a “witch” into confessing to “obscene acts with Satan”, and burns her to death, and the Christian who watches and cheers. That's the parent who beats their child senseless to drive out “evil spirits”. That's the person who tells women they have no place outside the home because “God says so”. That's the politician who tries to legislate that pregnant women should die rather than have access to life-saving care, because his religion tells him so.
And yet it is so commonly done. Why? Because it takes no courage to keep believing what you were taught. It takes no courage to hold to the beliefs of the majority of your country or region. It takes no courage to turn off your mind, and just nod along with what your pastor, priest or imam tells you. It's easy and self-satisfying to think that you are on the path of rightness; it's easy to push away any pangs of conscience, where they appear, with condemnations of the people you will hurt. Whereas it takes a great deal of courage and uncomfortable thought to put those beliefs to the test of reason, and discard them, no matter how cherished, where applicable. It takes a great deal of courage to say, “So what if my church teaches it; what if that isn't the right way after all?”
The fact of the matter is, every religion has been used to harm people, and most (even the most ardent) believers will agree that some at least of the actions justified by that faith were wrong. Slavery, oppression of women, racism, anti-Semitism, persecution and murder of gays, absolute monarchies, the inquisitions, heretic burnings, “holy wars”, purges of Catholics of Protestants, purges by Catholics of Protestants, Sunni on Shiite and Shiite on Sunni violence, etc., etc., etc. … all of those things have been justified, at one time or another (and a lot of them are still justified by some practitioners) by pointing to church teachings, holy doctrines, etc. Where these things have stopped, it's because people *started* questioning, started thinking, started reasoning for themselves. They stopped listening to people who told them “don't you dare question that!” and questioned anyway.
The power to reason is our tool against fear; reason is the enemy only of those who would keep others willing fools to be manipulated for their own political or financial gain, or to further their own prejudices and fears. Reason is the friend of anyone who would do right by their fellow man, and it is the friend of truth as well. Truth does not suffer from inspection, but rather profits from it. Only lies suffer from inspection. Thus I put no stock in anyone who tells me that I have no business questioning something. “How dare you question that doctrine?” is the equivalent of “My position is so weak that I dare not defend it with logic, thus I will resort to threatening you with hellfire!”