This is not to say that great art and writing requires Christianity. Far from it. But I think that art beyond a certain level requires belief in something beyond the everyday material reality. Homer wrote great poetry because he wrote of the struggles of men against fate and the caprices of the gods. Virgil dealt with the conflicting moral claims that resulted from an emerging sense of objective, philosophically-based morality vs. a lingering conviction that it was necessary to do the will of the gods. Norse mythology dealt with a pantheon which was itself doomed, and yet that sense of looming destruction also held out hope for a world reborn without the pain and conflict of the present one. All of these can inspire great art.
Perhaps because it is such a modern, urban, middle-class phenomenon, the current round of strident atheist writers project instead a sense of inward-looking self satisfaction. A smallness. How could someone produce much interesting in the way of art who adhered to Richard Dawkins’ “secular commandments” which include things like “Do not indoctrinate your children” and “Enjoy your own sex life (so long as it damages nobody else)”?