I regularly rail against the rhetorical tactics of strident atheists like Sam Harris, Christopher Hitchens and Richard Dawkins because they fail to realize that religion serves a legitimate human need, and that until atheism offers up a competitive substitute for that need it will fail to win hearts and minds. Yes, HH&D's books are bestsellers, but I think they're just preaching to the already unconverted. There is little evidence that they are actually winning over many people who were not already predisposed to rationality. Moreover, their conflation of relgion and fundamentalism is a dangerous fallacy. These are two distinct phenomena, and only one of them (fundamentalism) needs to be combatted.
The need that religion serves is the need to feel that life has a purpose, the need to feel that one is part of something greater than onesself, the need to quell existential angst. Let me concede up front that this need is wholly irrational, but just because something is irrational doesn't mean it isn't real.
When I was in college I had a serious relationship with a girl who lived 2000 miles away (I was in Virginia, she was in California). The rational part of me recognized that it was silly to expect monogamy in such a situation (to say nothing of the fact that I wanted to keep my options open) and I told her so. One day she told me that she had had oral sex with another man. The rational part of me said that this was no big deal. But deep in the dark evolutionary recesses of my brain there arose a powerful and completely unexpected emotion: jealousy. It took me completely by surprise and almost completely paralyzed me for days. At one point I tried to call her, but she was out, which of course made things worse. This was back in the 80's, before cell phones, before AIDS, before voice mail. I sat on the floor literally for several hours listening to the phone ring and ring and ring and ring and ring and ring and...
All the while, part of my brain knew that I was severely overreacting. But simply knowing that didn't make the feeling, or its physical impact on my life, any less real.
Of course, jealousy is irrational only from the point of view of a college student trying to carry on a long-distance relationship. From the point of view of my genes trying to compel me to help them reproduce it makes perfect sense. So too with existential angst. For most of their evolutionary history, humans existed at subsistence levels, always on the hairy edge of starvation. In such an environment, labor is a precious and valuable resource. Any extra hands available to hunt or gather or till or harvest contribute directly to survival. Such an environment selects heavily for instincts that in this modern age we would call a Puritan work ethic, and a belief that human life (which is to say, labor) is precious.
The advent of economic plenty brought about by the indusrial revolution changed everything. Suddenly everything became cheap including labor. It was suddenly possibly for members of the clan to engage in activities not directly related to the production of food without putting the other members in peril of starvation. People could become scholars or poets or even outright parasites (c.f. Paris Hilton) without being strongly selected against, at least not by evolution.
Moreover, labor, once a precious resource, became a commodity. Which is to say that people became a commodity. With division of labor, standardization and specialization, humans were essentially turned into machines, at least in the workplace. All this was enormously beneficial in societal and evolutionary terms (as evidenced by the fact that humans are now overrunning the entire planet) but from the point of view of the human instincts and emotions evolved during leaner times it was a disaster. Our genes evolved a wide variety of dirty tricks to make us want to work hard, to be useful, to be part of something greater than ourselves, to feel like our life had a purpose, to believe that God Himself wanted us to be fruitful and multiply. Barely an eyeblink ago in evolutionary terms these instincts had real survival value. Today they don't, but the gears of evolution turn slowly and those instincts and emotions are still with us, and no less real and impactful on our lives than jealousy.
The reality of these instincts is manifest -- there is no other way to explain the rise of fundamentalism in the modern world. Many authors have written about this, including Karen Armstrong and Michael Lerner. The modern resurgence of fundamentalism is an instrinctive response to the dehumanizing effects of modern industrial society. We evolved to believe that human life is precious because we evolved in a world where that belief had survival value.
Of course, DD&H understand all this. (This is actually the central thesis of "The God Delusion.") What they do not understand is that they are outliers. Random variation naturally produces some people in whom these instincts are less strong or even absent altogether, and with the old evolutionary pressures removed these outliers begint to survive and become more common. But DD&H apparently fail to realize that the vast majority of people cannot simply switch off their instinctive desire for meaning, community, and purpose, even if that desire has to be fulfilled by beliefs that are objectively fictional.
The objective fact of the matter is that human life is no longer precious, which is just another way of saying that labor is cheap. Most people are confronted with this harsh reality every day when they go to work. Modern industrialism has transformed humans from precious individuals to interchangeable components. Evolutionarily it has been a great success. We can now, for example, afford to slaughter each other wholesale with nary a blip on the exponential population curve. But evolution works slowly, and those not-so-old instincts are still with us, and it is very, very hard to shake off the burden of instinct. These feelings are wired deep into the dark recesses of our brain, and logic is a poor weapon against the power of evolution.
Until DD&H realize that for many people religion is just as much a compulsion as reason is for them they will continue to fail to win hearts and minds. And that is a damn shame.