Wikipedia has a great deal of information on C.S. Lewis. A Christian convert later in his life, it has been said that this particular installation of the Narnia tales was based on Christ.
Lewis... preferred to call the Christian aspects of them "suppositional".
In reality, however, he (Aslan) is an invention giving an imaginary answer to the question, 'What might Christ become like if there really were a world like Narnia, and He chose to be incarnate and die and rise again in that world as He actually has done in ours?' This is not allegory at all.
Like any good movie or book, it's filled with archetypal figures: the hero, the martyr, the unbeliever, the innocent, the traitor, the evil one, and the savior.
I love the casting and costuming of the White Witch (Tilda Swinson). The costume department must have had a blast doing it! Especially in the battle scene, where she's driving the pair of polar bears. Magical!
Rent it and enjoy it! hugs- Lee