A little while ago a friend of mine took it upon himself to post on my Facebook wall a rather scathing response to my general tendency to post content lampooning or criticizing religious beliefs. After a bit of (refreshingly civil and productive) back-and-forth, we came to the conclusion that the most important difference between him and me (and likely between many others and me) is simply this: he believes that peoples' personal beliefs deserve respect, whereas I obviously do not believe this to be true. I feel this is an important topic for discussion, because not only are we not obligated to respect peoples' personal beliefs, the fact is that we actually do not.
First I'd like to draw the important distinction between respecting beliefs and respecting individuals. I do believe that all human beings are worthy of some measure of respect, by virtue of our own common human experience and recognition of basic human dignity. It is also true that every person is entitled to believe whatever he wants and express those beliefs publicly. It does not follow, however, that the rest of us are obligated to be respectful of the beliefs of others, and it should become obvious why this is so.
It is important to realize that the taboo on criticizing religious beliefs is actually a product of our ever-softening, liberal, don't-hurt-anyone's-feelings, politically-correct attitude toward everything and everyone. The guilty people in this case are moderates - people who want to play both sides and make sure that nothing is ever said which might make people uncomfortable. Religious fundamentalists in this country freely and openly criticize other religions, or even different denominations or flavors of their own religion. There is a portion of the population which is perfectly comfortable saying things like "Islam is evil" and "all Muslims are terrorists," for example. Even if those beliefs are bigoted and ignorant, at least those people aren't being held hostage by their own hypersensitivity.
There are a few problems with religious moderates, and unfortunately they are fairly large problems with serious consequences. The first problem is that it is intellectually dishonest to assert that we can and must respect the beliefs of others. In every other realm of subject matter, "respecting beliefs" does not even enter into the discourse. Take, for example, a conversation between you and an interlocutor who believes very strongly that the Holocaust never actually occurred and is simply propaganda. You would promptly and rightly dismiss this person's beliefs as ignorant at best and utterly offensive at worst, and you are under no obligation whatsoever to respect this belief, no matter how strongly this person holds it. Now consider how alarmed you would be if you then discovered that this person was your child's history teacher, or if at a presidential debate a candidate openly expressed this belief.
Sam Harris gives a more absurd example of this line of argumentation. Imagine your neighbor has a deeply-held belief that there is a diamond the size of a refrigerator buried in his yard. This is manifest lunacy; yet imagine also if your neighbor said the sorts of things that religious people say to justify it; "well, this belief that there is a refrigerator-sized diamond buried in my back yard gives my life meaning," or "I wouldn't want to live in a world in which there wasn't a refrigerator-sized diamond buried in my back yard." Obviously not all beliefs deserve to be "respected," and we regularly dismiss the beliefs of others in this way.
Consider for a moment how absurd it is to have to tell someone to respect your beliefs. Again, respect never enters into the evaluation of ideas. When you express your ideas or beliefs to someone, he will evaluate your statements and come to a conclusion about their validity based on reason. If your assertions are consistent with reality and seem plausible, he will unconsciously and helplessly accept them as true. If they are at odds with reality and seem implausible, he will reject them as improbable or false. We do this subconsciously every time we are confronted with new information, and going through this process helps us to be confident in what we know to be true. If you present your beliefs to someone who evaluates and then rejects them because they do not square with what seems to be true about the world, it is unreasonable then to command this person nevertheless to consider your beliefs as equally valid or "respectable" simply by virtue of the fact that you believe them. As demonstrated above, we are not in the habit of doing this in any other subject of discourse, and for perfectly good and necessary reasons.
Besides being intellectually dishonest, religious moderation is also theologically vacuous. Herein lies the most pernicious problem with the complete unwillingness to criticize religious beliefs. When we grant that certain books have divine authorship and are above criticism, we become completely and helplessly subject to the content of those books. When we assert that people are entitled to their beliefs and we mustn't interfere or be critical of them, we become powerless to address the very real problems that religious views are imposing on the world. Moderates desperately want to believe that religious extremists are just a fractional group of fringe lunatics who completely misinterpret the texts of their holy books. This is a delusion. The truth is that anyone with a Bible or Koran in hand can readily find justification for doing acts of unspeakable horror because it is the will of God. The men who flew hijacked planes into the World Trade Center believed that they were doing good and would be duly rewarded for their martyrdom, and this is not a warped, insupportable reading of their holy book. The fact that not every single Muslim murders infidels does not negate the fact that one can easily find passages in the Koran supporting and validating this behavior.
Although thankfully not as barbarically murderous, beliefs held by Christians justified by the Bible are also perpetuating unnecessary human suffering. Stem cell research has been repeatedly thwarted or hindered by lawmakers based solely on the unsubstantiated belief that a collection of a few cells in a petri dish has a soul and cannot be destroyed, even if it means medical advances for thousands of actual human beings. Catholic missionaries in AIDS-ravaged Africa continue to preach the sinfulness of condom use to people whose lives would be saved by safe sex education. As soon as someone is questioned as to why these practices are acceptable, a simple retort of "it is my faith" completely halts all conversation or progress. We have collectively agreed that it is a virtue to say "I believe X because I believe it on faith." The problem with this is that these ideas have real consequences, and we can see in various religions throughout the world that people of faith can find completely logical, reasonable justifications for doing literally anything based on what they believe on faith.
Instead of being critical, politically-correct moderates want to ignore the problem, pointing out that most people of faith do not behave this way. It's true, thankfully they don't. But we become completely incapable of having a discussion about the people who do, and that severely limits our ability to do anything about it. Either the beliefs of the pious, devout Christian and the suicide bomber are both open to criticism, or neither of them is. Hopefully the problem with the latter is clear.