This may just be me being a lit snob (or church snob--it kind of blends in this case).
I've found, in recent weeks, a veritable outbreak of books that claim to peel back the layers of mystery surrounding the Chronicles of Narnia, and reveal the super double-plus secret (gasp!) Christian messages contained therein.
Literally dozens of books seem to have been written on the subject. I noticed the same thing occuring (though not in this magnitude) when The Lord of the Rings was filmed. Back then, I could understand it. LOTR is primarily a fantasy epic, and while I'd argue that spiritual themes are certainly present in the books, they aren't that obvious sometimes.
On the other hand.
Let's just pull something out of the air, shall we? How about: Aslan the God-like Lion dies in place of Edmund, and then comes back to life and defeats the Enemy.
Hmm. I wonder who THAT's about. (And don't say The Fisher King.)
Yet here we are, in a deluge of books about the "hidden, secret themes" in Lewis' painfully obvious allegorical works. (And if you want to pull quotes that say he didn't really mean them to be, fine, but I cry BS anyway.)
Maybe it's just me. Maybe it's a situation like one of those Stare-o-gram pictures, in which there is a hidden picture amongst the lines and squiggles. Once you see it, you can't un-see it. Or to cop another, greater Man's line: If you have ears to hear, you're gonna hear it.
So, sure, for those who aren't steeped in Christian tradition, such a guidebook might be helpful. But do you know what would be more helpful? Here, I'll whisper it in your ear. What would be most helpful and effective in explaining the Gospel message in CON to unbelievers is...
Not books. Not advertising campaigns.
When I see these books in the Christian bookstores (and almost nowhere else), I have to admit, all I can think is, "Great, another book that does the thinking for us--way to go, church!" Because I believe that, if you have ears to hear, you're gonna hear it. And if your ears are not attuned to hearing the truth of God outside of your cathedral walls, you don't need to read a book about a book. You need to read the book itself. And maybe the Other Book along side it. You need to sit next to a lake at dawn, and see the mist rise on the water. You need to listen to "The Joshua Tree." You need to read "Les Miserables." You need to train yourself to listen for truth on cicada wings. Because He reveals himself to us in the sunset and in the sunburnt troubador. In the pulpit and the pen of the honest author.
If you read these types of books, the "finding the hidden meaning of" books books, don't take this as a slight. I'm really not making fun of you, I promise. I'm just saying, you know, you may not need that at all. Stretch yourself a bit more, and you'll get there on your own. You've got a Good Teacher and Counselor to walk the path with you.