That's how I've known him of old, for books like Mere Christianity and Miracles (whew! now there's one that'll twist your brain). I always knew he had written the Chronicles of Narnia, but had never gotten around to reading them. The Christian influence is pretty clear and we'll get to that in a moment, but it was the mixing of that with the magical and mystical which intrigued me most. Elements of the story like Mr. Tumnus the faun, the centaurs, the Dryads and all the rest are part and parcel of the world Lewis created. Even the evil creatures like the Incubuses, Efreets and Minotaurs have their roles to play. These things all come from different cultural traditions, but are woven seamlessly into the story. Perhaps it comes from living in a time when the pendulum is swinging back towards religious fundamentalism, but I found comfort in such nonjudgmental presentation. Make no mistake, however, this is a Christian book, though perhaps not exclusively.
The story goes that when Lewis started writing the Chronicles, he and J.R.R. Tolkien (a close friend and colleague) got into an almighty row over the books. You see, for most of his life Tolkien held a very public hatred for allegory of any kind. Whatever your feelings on the subject, there are no two ways around it - this book is heavy on symbols. Aslan is Jesus Christ. The Witch is the Devil. Peter is Peter, for crying out loud. There were times, like Aslan's sacrifice, when I thought Lewis was laying it on rather thick. The Deep Magic and the Deeper Magic, which go largely unexplained, seem like convenient excuses for why events unfold the way they do. In these places, I could understand Tolkien's perspective. Overall, however, I didn't find it that much of a drag on the story.
I think I was able to make my peace with the allegory because it's not just part of the story, it is the story (which brings me back around to the title). The lion, the witch and the wardrobe are in the title because they are the three most important things in the book. The wardrobe is the entry point, the beginning of a journey to Christian faith. Along that journey, the Devil will be encountered. He (she in the book, I suppose) is a part of the world, but not really in control of it, just as the Witch doesn't really rule Narnia. Nevertheless, there will be times of trial on the journey, when the Devil is hot on our collective heels. In the end, though, we find the lion/Christ/faith and He saves us from all that the world can do to us.