worldbuilding, storytelling and atheism

"Atheists can write perfectly good and realistic fiction, because there is nothing about being an atheist that prohibits a person from understanding human motivation and the physical world. But being nonreligious does deprive you of the one thing an ambitious fantasy author needs: a plausible cosmology, a myth that tells us how things got to be the way they are. The great religions all provide this. One could even hold, as did Lewis and J. R. R. Tolkien, that a religion is just a story of the world, which in the case of Christianity (they held) happens to be true. A Christian fantasist in his act of subcreation can borrow heavily from the true mythic world created by the Christian God; the fantasist might change some of the names and other details, but the basic infinitely rich story has already been told.

The nonreligious fantasy author is forced to play the mythmaker twice, as it were. He has to develop a cosmology of the way the world really is, the nonreligious account that re­ places the account given by the religions he rejects. And he has to write the fantasy story, obeying all the rules of the larger account and then creating his own world within it."

-Daniel P. Moloney, in this article about the His Dark Materials books