The whole structure of postmodernism is built on a new view of the limits of reason. Science seems to confirm that reason only takes us so far. It is very good for solving practical problems, but not for solving the mysteries of the universe. We don't know if the universe is rational, if it is really built on the same logic used by the brain to solve problems. We can't climb out of our brain to verify the truth of our insights and first principles. As Heidegger said, we are like a fly in a bottle.
For example, is it true that events and things are really separate as our brain sees them? And there is the problem of language, which filters, interprets, and organizes our perceptions. The postmoderns say that the foundation of our knowledge is not reason, as the rationalists say, or emotion, as the romantics say, but language. We are born incomplete and language completes us. We are creatures of language. Reality becomes what we say it is. When we define things as real, they become real in their consequences.
What does this mean for atheism? Well, first of all, it means we are on the wrong track criticizing religions for their lack of reason. Both Christianity have been intensely rational. Their adoption of philosophy of the Greeks may explain their history of absolutism and intolerance. The 18th-century declaration of papal infallibility was based on the lock-step application of reason to an ancient mythic document that was never meant to be understood that way.
Postmodernism allows us to see how much of our lives is governed by the irrational. Even the great discoveries of science resulted not just from method and discipline, but from sleep deprivation, inebriation, whimsy, mistakes, and wild guesses. As Einstein said, "If at first the idea is not absurd, there is no hope for it."
That is why postmoderns put their hope not on reason or science, but on language, poetry, and fiction, which can create new worlds, contexts, and paradigms for pursuing peace, health, and happiness.
What this does is give atheists a way to break out of their shell of being anti-religious. We do not have to oppose the revelations of mystical experience. What we can oppose are the rationalist, authoritarian structures that exploit those experiences to create absolutism, intolerance, and atrocity.
Rather than rejecting religion as an irrational belief, we can see it as an almost universal experience. It has contributed to what makes us what we are and how we think.
What makes religion so dangerous is its intolerance. Do we have to be intolerant of religion? For all we know, Zeus and his pals might really be out there. Religion seems to be very good in presenting new visions of life. If they do help people become more peace-loving and tolerant, is that so bad? Cannot an atheist embrace religious experience without submitting to the constraints of dogma?