Religion is tempting, it allows for an abnegation of thought and responsibility, it provides rules and standards without the requirement of moral consideration needing only obedience. Religion provides easy answers for everything you ever worried about without the need for education. It gives you a support network, a book of guidance, a convenient enemy to blame when things go wrong and the promise of an eternities worth of chocolate and niceness after you don't "really" die.
It turns life in to a cross between reality TV and Sesame street and will kiss better every booboo (or at least tells you it will) and makes you forever a grateful child with the big sky daddy to watch over you for ever and ever.
All sounds pretty tempting until they turn on you like a rabid dog for daring to to ask questions or announcing you might just be a bit different and need acceptance.

My 2 cents: the world, country, state, county, city or farm that one lives on / in is a very complex place. Worrying about everything can be intensely frustrating. I think adults turn to religion as it is time for them to zone out -- become one with the holy ghost (like a herd of cows staring at a passing train). They don't have think about anything. It is restful, in a way. They then condition their children to something they cannot explain but think is a good way to live. Learning to deal with world is something the masses have difficulty with.

Bill mentions Jimmy Carter. A few years back some friends and I drove to Plains, Georgia to sit in on Jimmy's Sunday School class at the Maranatha Baptist Church. It was not what I had expected. He used Bible stories to illustrate moral issues relevant to today's real-world events. The real subject of his entire talk was American and World politics today, not 'why you should turn your life over to Sky Daddy.' It was pretty clear to me that Jimmy Carter understood his religion as metaphor that was useful for communicating complex subjects to ordinary people by way of symbolic stories. I can just about guarantee that's the way Bill Moyers understands religion too, as well as many, if not most, broadly educated religious people.

Sam Harris doesn't answer Bill Maher's question well because he doesn't know religion from the inside. And specifically, religion that has not bought into the fundamentalist distortion. There are homes in which children are raised with religion as illustrative metaphor, rather than as oppressive dogma. These people aren't "disordered," they are just culturally literate.

As with all things living, of course, it's nature and nurture. The nurture part is not too hard to understand; we are, to an extent greater than we sometimes recognize, products of our culture. Though it is widely understood that our upbringing can be a persistent influence on our outlook, the biological part, on the other hand, is not common knowledge. In his book, "The Illusion Of God's Presence" biologist John Wathey makes a very convincing case.

From the Amazon ad:

"An essential feature of religious experience across many cultures is the intuitive feeling of God's presence. More than any rituals or doctrines, it is this experience that anchors religious faith, yet it has been largely ignored in the scientific literature on religion. Starting with a vivid narrative account of the life-threatening hike that triggered his own mystical experience, biologist John Wathey takes the reader on a scientific journey to find the sources of religious feeling and the illusion of God's presence. His book delves into the biological origins of this compelling feeling, attributing it to innate neural circuitry that evolved to promote the mother-child bond. Dr. Wathey, a veteran neuroscientist, argues that evolution has programmed the infant brain to expect the presence of a loving being who responds to the child's needs. As the infant grows into adulthood, this innate feeling is eventually transferred to the realm of religion, where it is reactivated through the symbols, imagery, and rituals of worship. The author interprets our various conceptions of God in biological terms as illusory supernormal stimuli that fill an emotional and cognitive vacuum left over from infancy. These insights shed new light on some of the most vexing puzzles of religion, like the popular belief in a god who is judgmental and punishing, yet also unconditionally loving; the extraordinary tenacity of faith; the greater religiosity of women relative to men; religious obsessions with sex; the mysterious compulsion to pray; the seemingly irrepressible feminine attributes of God, even in traditionally patriarchal religions; and the strange allure of cults. Finally, Dr. Wathey considers the hypothesis that religion evolved to foster reproductive success, arguing that, in an age of potentially ruinous overpopulation, magical thinking has become a luxury we can no longer afford, one that distracts us from urgent threats to our planet. Deeply researched yet elegantly written in a jargon-free and accessible style, this book presents a compelling interpretation of the evolutionary origins of spirituality and religion."
[amazon.com]

They might have had a personal existential crisis. Through all the fluff of rituals and dogma, maybe there is, after all, something in religion that they need for survival. It’s irrational I know, but humans are not always rational. Logically, our response should be to respect them and to respect their choices, to seek to understand rather than to be understood.