Not even remotely, blacksinow. Tolkien is considered the father of modern fantasy. Lewis, not so much. It may have some stronger appeal in deeper christian circles for it's allegorical elements, but both as an influential piece and my opinion, a work of art, it falls painfully short of Lord of the Rings.
Tolkien was not an atheist, as much as I'd like to claim him, he was staunchly Catholic. Like speak-only-Latin-in-mass-even-though-they-switched-over-to-english sort of Catholic.
As for his works being Christian, Tolkien abhorred allegories and left the interpretation of the work to the individual reader (you know, like art), but in his letters, he mentioned that it was not intentionally catholic at in it's first draft, but in the rewrites it was. For him, it was a christian work. For you, it can be whatever you want to read from it. That's how Tolkien would have intended it, to find the truths from your own life.
EDIT: Oro's post got in before mine. I very much agree with Orodrist, he was an avid mythology aficionado and set to make his own.