Contrary to popular belief, atheism is not primarily an intellectual revolt; it is a moral revolt. Atheists don’t find God invisible so much as objectionable. They aren’t adjusting their desires to the truth, but rather the truth to fit their desires…It is a temptation even for believers. We want to be saved, as long as we are not saved from our sins. We are quite willing to be saved from a whole host of social evils, from poverty to disease to war. But we want to leave untouched the personal evils, such as selfishness and lechery and pride. We need spiritual healing, but we do not want it. Like a supervisory parent, God gets in our way. This is the perennial appeal of atheism: it gets rid of the stern fellow with the long beard and liberates us for the pleasures of sin and depravity. The atheist seeks to get rid of moral judgment by getting rid of the judge.Dinesh D'Souza in What's So Great About Christianity
I have had a number of occasions to have long conversations with self-described atheists. I can tell you that every single one of them fit D'Souza's quote to a tee. They were really rejectionists more than atheists, for they certainly believed in God. They just hated him.
By far in this era, the primary reason - so far out in front that it leaves the rest so far behind there's no point on even figuring what's second - is the rejection in America today of any sort of connection between morality and sexuality. "If it feels good, do it" is the overwhelming mantra of the modern age.
The easiest way to justify sin is to deny that there is a creator to provide reality with a nature, thereby denying that there is any inherent order and purpose in the universe. Aldous Huxley admitted that this is a common reason for skepticism:
I had motives for not wanting the world to have a meaning; consequently I assumed that it had none and was able without any difficulty to find satisfying reasons for this assumption…. Those who detect no meaning in the world generally do so because, for one reason or another, it suits their books that the world should be meaningless. …
For myself as, no doubt, for most of my contemporaries, the philosophy of meaninglessness was essentially an instrument of liberation. The liberation we desired was …liberation from … a certain system of morality. We objected to the morality because it interfered with our sexual freedom…. There was one admirably simple method in our political and erotic revolt: We could deny that the world had any meaning whatsoever. Similar tactics had been adopted during the eighteenth century and for the same reasons. (Ends and Means, 270-273)
Thomas Nagel, American philosopher, currently University Professor of Philosophy and Law at New York University:
I want atheism to be true and am made uneasy by the fact that some of the most intelligent and well-informed people I know are religious believers. It isn't just that I don't believe in God and, naturally, hope that I'm right in my belief. It's that I hope there is no God! I don't want there to be a God; I don't want the universe to be like that. My guess is that this cosmic authority problem is not a rare condition and that it is responsible for much of the scientism and reductionism of our time. One of the tendencies it supports is the ludicrous overuse of evolutionary biology to explain everything about human life, including everything about the human mind… This is a somewhat ridiculous situation… [I]t is just as irrational to be influenced in one’s beliefs by the hope that God does not exist as by the hope that God does exist. (The Last Word, pp. 130-131)Quoted by fellow philosopher Edward Feser.
Perhaps Werner Heisenberg, who won the Nobel Prize in Physics for creating quantum mechanics, explained the divergence between biology and physics (with regard to God) best when he wrote:Link.“The first gulp from the glass of natural sciences will turn you into an atheist, but at the bottom of the glass God is waiting for you.”With the phrase “the bottom of the glass,” Heisenberg is referring to the study of the most fundamental aspects of reality…which are investigated by physics.