I am referring to what happens in Narnia as magic so that I can draw distinctions between the two movies. When God performs a supernatural act, I do not call it magic, and as such, what happens in Narnia is not magic, but the supernatural hand of God.
In Potter they celebrate the commercialized humanist Christmas. It is presented as a break from school, not to celebrate Christs birth. I know a lot of people that celebrate Christmas but do not believe in Christ.
If a Christian had "power" to perform "magic", then upon changing allegiances, the power of magic would also change. God does not serve man, man serves God. Before any "magic" could occur, one would have to devote themselves fully to thier God. Potter has numerous characters that perform magic "for good" and something evil happens, or perform magic for evil and something good happens.
The closest you could get to that in Narnia is Edmund, who sins (no magic), and is claimed by the Ice Witch (Satan) because of his sin. God (Aslan) offers himself in his place, is killed and resurrected, and then breaks the gates (castle) of hell and sets the captives (saints that stood up to Satan) free on his way to saving the world. That is a pretty heavy duty line by line comparison to Christianity, that Potter cant touch.
The characters in Narnia speak directly to Aslan (God). In a later books, you will hear Aslan tell the children he was waiting for them to call on him.