The following is an excerpt from C.S. Lewis’s first of three published letters to Sheldon Vanauken. This one was written on December 14, 1950, and briefly compares religious and philosophical systems. Lewis’s argument for the superiority of Christianity is interesting. His evidence here does not lead to a necessary conclusion, but it is certainly thought provoking:

…I believe Buddhism to be a simplification of Hinduism and Islam to be a simplification of Xianity. Clear, lucid, transparent, simple religion (Tao plus a shadowy, ethical god in the background) is a late development, usually arising among highly educated people in great cities. What you really start with is ritual, myth, and mystery, the death & return of Balder or Osiris, the dances, the initiations, the sacrificies, the divine kings. Over against that are the Philosophers, Aristotle or Confucius, hardly religion at all. The only two systems in which the mysteries and the philosophies come together are Hinduism and Xianity: there you get both the Metaphysics and Cult (continuous with primeval cults). That is why my first step was to be sure that one or the other of these had the answer. For the reality can’t be one that appeals either only to savages or only to high brows. Real things aren’t like that (e.g. matter is the first most obvious thing you meetmilke, chocolates, apples, and also the object of quantum physics). There is no question of just a crowd of disconnected religions. The choice is between (a.) The materialist world picture: wh. I can’t believe. (b.) The real archaic primitive religions; wh. are not moral enough. (c.) The (claimed) fulfillment of these in Hinduism. (d.) The claimed fulfillment of these in Xianity. But the weakness of Hinduism is that it doesn’t really merge the two strands. Unredeemable savage religion goes on in the village; the Hermit philosophizes in the forest: and neither really interfaces with the other. It is only Xianity which compels a high brow like me to partake of a ritual blood feast, and also compels a central African convert to attempt an elightened code of ethics. – C.S Lewis