(Note to the curious: a good knight wears shining armor because he keeps it in good shape, without rust.)
So I'm meandering along and working on the metaphysics and stuff and conclude -- no this is not a Christian setting. Any more than C. S. Lewis could have made Till We Have Faces in a Christian setting. Nevertheless, if I am going to have knights in shining armor, I've got to have an equivalent religion. . . .
Monotheistic, of course. Polytheistic is right out as a Christian counterpart, being so different from monotheism that historically, many sorts of philosophers have been been both. Still, to feed into the proper religious structure, this has to be a popular monotheism. Indeed, I've done one before, where, since the story focused on the vicissitudes of life, I conjured up the Lady of Permutations. And there's always the forces of Light, though that would need some serious work to develop past the the standard.
But here -- ponder, ponder, ponder. What is the concept that most needs to be foregrounded in the work. . . .
You would think it would be war and justice for knights, perhaps, but I think perhaps this one emphasizes order. (Perhaps I can rip off the notion of oysters being the lowliest of animals from the Elizabethans.)
Hmm. . . to be sure, order and justice would probably be closely intertwined in this sort of society. Though there is the difficulty of conveying the the modern-day reader that they really think the social structure from the least to the greatest a matter of justice. As I observed in Orwell's essay on Yeats, he thought that anything non-egalitarian was intrinsically unjust, and he's not alone there.