One of the problems with Christian Fantasy that I have seen is in how it steps through the looking glass. This is a problem that isn’t unique to Christian Fantasy, but it is a problem that Christian Fantasy authors must handle if they hope to succeed. Some have and some haven’t.
The Fantasy author must find a way to step through the looking glass with his story. If he doesn’t, the reader will apply the rules of our Universe to the universe of the story. When we write, we want to create the suspension of disbelief. That is more difficult in Fantasy when the story closely approximates our world. If the Fantasy author tells us that there are elves living among us, we are willing to suspend our disbelief for the space of the story, but suppose he tells us that the 9/11 attacks were planned by our government. We will refuse to accept that.
Creating the suspension of disbelief requires a few things we can’t prove. While we have never seen elves, we can’t really prove they don’t exist. The facts about the 9/11 attacks are widely known and provable. Christian Fantasy has an additional problem that ordinary Fantasy doesn’t have in that it must assume the Bible to be fact. When Christian Fantasy suggests something that is inconsistent with the facts in the Bible the suspension of disbelief fails.
The solution for an author who wants to tell about 9/11 in a different way is to create an alternative universe. This is very similar to the Science Fiction author’s parallel dimension. C. S. Lewis accomplished this by sending children through a wardrobe. Once on the other side, all of the facts that we once knew are no longer in evidence until we reestablish them, so if our story does something like blame 9/11 on someone else or says the Nazis won then there is no way for the reader to prove otherwise.
A couple of things seem to work well. The most obvious solution is a portal type story. Alice stepped into a rabbit whole in one story and through a looking glass in another. Encapsulating the story in a dream or a story as told by someone else will also work to move our reader from this world to another. The other thing that works is to simply dump the reader into a world that is so strange that the reader just assumes it isn’t our own. Telling the story from the point of view of an elf will do that for us.