Dumbledore Beats St. Paul
And if Christ has not been raised, our preaching is useless and so is your faith. ... And if Christ has not been raised, your faith is futile; you are still in your sins.
-- St. Paul, 1 Corinthians 15: 15 and 17
Of course it's all in your head, Harry, but why should that mean it isn't real?
-- Albus Dumbledore, Harry Potter and the Deathly Hallows
The first quote above is one of the cornerstones of the prevailing modern approach to Christianity. This is the "authoritative truth" approach, in which what is essential in Christianity is to believe in the truth of certain doctrines about God and Jesus. Following St. Paul, the argument is that Christianity is meaningless if Jesus was not literally the son of God, did not actually get crucified around 33 CE in Judea, and did not really rise from the dead three days later. The emphasis of Christian work is then evangelizing this truth.
When the truth of the stories in the Bible becomes central to what Christianity is about, then a conflict between the authority of faith in (one interpretation of) the Bible and other sources of truth becomes inevitable. Christians are forced to take on evolutionary biology, either engaging in pathetic mental gymnastics to reconcile Genesis and Darwin or brazenly denying the legitimacy of science. And you get spectacles (which would be funny if so many people didn't sincerely agree) like apologist Josh McDowell decrying the internet for exposing young people to non-Christian ideas and tempting them to exercise skepticism about things they're told.
I juxtapose St. Paul's quote with Dumbledore's because some elements of Harry Potter fandom do a much better job of capturing what really ought to be important about religion. With the Harry Potter books, there's no question that the stories are fictional -- there is no Harry Potter, there is no Hogwarts, there is no real magic. And yet, as this great article describes, the fan community that has grown up around the books offers much of the same things that religion has traditionally offered. Harry Potter fandom brings fellowship, inspiration, personal guidance, and the organization to do good in the wider world. The article's descriptions of the fan community's activities, and particularly of the charity-oriented Harry Potter Alliance, match up with what I've heard from a good friend who was heavily involved in the fandom and HPA for many years (I myself have only read the first book). And yet Harry Potter fandom manages to do all that without asking you to believe the stories are true. The stories function as myths in the anthropological sense -- they give the community a common reference point and a language for talking about and exploring their values. The stories in the Christian Bible could and should function that way too (I know I find value in many of them despite being an atheist), but modern Christians are too hung up on the alleged vital importance of their literal truth. One of the things that drew me to Unitarian Universalism was the idea that we could choose the myths that were genuinely inspiring and useful, rather than worrying about whether they actually happened (I recall one service where our reading was from the Dead Marshes section of Tolkien's The Two Towers).
My point is not that truth doesn't matter or is relative -- without accurate information about the situation on the ground in Haiti and what aid strategies are effective, HPA's efforts to help really would be in vain. But the point is that communicating facts about the world is not the function of myths, be they found in ancient scriptures or contemporary young adult novels. Insisting that all religion (or things-serving-the-functions-of-religion) must follow the authoritative truth model prevents atheists from seeing the value in religion just as much as it locks religious people into a protective echo chamber.
Getting away from the authoritative truth model also allows a community to be evolving and self-critical. J.K. Rowling may be a brilliant and inspiring writer, but she's not God. So fans are free to criticize the cheesy heteronormative epilogue, or the treatment of the house elves, and reconstruct the story in their own way. This is much like the way folktalkes and mythologies in nonliterate societies work, and it allows people to rethink and readapt their belief systems. On the other hand, fixating on the authoritative truth of the Bible prevents you from altering one jot or tittle of the canonical version. Where Harry Potter fandom gains strength from embracing fanfic, Christians must brand their fanfic writers heretics. The ability to evolve, and to be honest about the fact that you're evolving, is vital.