In context; interviewer's question followed by Bainbridge's answer:
You've done a lot of work with religion. What does religion in WoW tell us about the real-world phenomenon?
The horrendous question that always troubles me is, what if religion is factually false but necessary for human well-being? What does science do then? Could there be some other stage of development in which we express ourselves through a kind of protean self in numerous realities with different levels of faith or suspension of disbelief appropriate to each of them?
That, on a much smaller scale, is what is happening with the fictional religions in WoW. The overwhelming majority of the people that play WoW don't take its religions seriously.
The difference between faith and fantasy might not have been very distinct in ancient times, and it's possible that we will move towards a time when instead of religion, people's hopes can be expressed in something that's acknowledged to be a fantasy but also, on some level, sort of real. WoW might exemplify that kind of post-religious future.