I’m not sure why it works because it ought to feel like a cheat, oughtn’t it?

As I may have mentioned before, it worked for me because at the time when I first read the books, I knew more about year-kings and solstitices than I did about Christianity and so it didn't matter if I didn't recognize the sacrifice and resurrection of Aslan as paralleling those of Christ, I understood perfectly that the sun was slaughtered at midwinter and came back with a lion's mane of rays and then the world began to warm again; Lewis had built in a perfectly decent pagan backdoor.