Sigmund Freud, writing about religion in The Future of an Illusion, asked, "Am I to believe in every absurdity? If not, why this one in particular?"
Even though he was talking about belief in God his question has resonance beyond its implicit criticism of theism. Consider, for instance, just a few of the absurdities that an atheist, like Freud, often chooses to believe:
He often chooses to believe that there are moral values that somehow transcend human subjectivity even though there's no basis for believing such things exist in a world without God. Unless there is a God the only morality that makes any sense is one based upon "might makes right."
He often chooses to believe that his daily existence has some meaning when in fact an eternal death nullifies all meaning and significance in life. Life can only have genuine meaning if physical death is not the end of one's existence.
He often chooses to believe that consciousness can arise out of brute material substance, as if a test tube full of the appropriate chemicals could produce a hope or a wish. There is no materialist explanation for human consciousness. It is a mystery. Why then is it less absurd to believe it somehow arises out of matter than to believe it somehow arises out of the mind of a Creator?
He often chooses to believe that even though everything in his philosophy tells him that we are just lumps of mud and blood, nevertheless we have dignity. On the contrary, human beings have no inherent dignity. Whatever dignity we possess is simply what we and others choose to confer upon ourselves.
He often chooses to believe that human rights somehow exist apart from the whims of the people in the state who wield power. He believes this even though any rights that the state chooses to grant its citizens are purely arbitrary and grounded in nothing more than human sentiment. We only have real rights to the extent they are granted to us by a transcendent moral authority.
He often chooses to believe that though this universe in which we live is so incredibly and exquisitely fine-tuned for life it is nevertheless just an accident of chance. He seeks to evade the powerful testimony of the universe's amazing physico-chemical properties by speculating that there are a near infinite number of worlds and that therefore at least one must have the astonishing collocation of properties, laws, and forces that this one has. He believes this despite the complete absence of any evidence for any world (universe) other than this one.
He often chooses to believe that the origin of life, the emergence of whole libraries of information contained within the walls of a microscopic cell, was a result of blind, unguided processes, as if feeding magnetic scrabble letters into a blender could eventually churn out the Encyclopedia Brittanica. Like consciousness, the origin of life is a complete mystery.
The Christian theist believes that the universe is not an incomprehensible coincidence, that consciousness is not an emergent property of matter, that life has meaning, human beings have worth, and morality and human rights are warranted because all these things are created by and/or grounded in an intelligent, personal God.
So we may ask Freud why it is more absurd to believe that there is an intelligent Creator than it is to believe that meaning, morality, the cosmos and life, human dignity and rights, all exist apart from any apparent or plausible ground or explanation for them. The fact is, it is the atheist who, in the light of what we know about the world today, must embrace absurdity.