I'm going to be perfectly honest with you. My first reaction to this sort of questioning is twofold:
-I don't know.
-Who cares?
That said, these concerns can be addressed with "it can't hurt to try and find out" and "you do", respectively, so okay, let's go.
I would say that A Christmas Carol is not a specifically Christian story, but it did come from a culture immersed to its eyeballs in Christianity, so it can't help but be colored by it in some fashion. And it's not difficult to see how its message of charity and community can be co-opted by Christians to great benefit. But then again Christianity still doesn't have a monopoly on that message. It could work with a cruel daimyo being visited by three kami, and it could work with a drug dealer who takes a bong hit too many and is visited by three hallucinated manifestations of his own guilt. The Christmas setting is just a perfectly convenient way to convey the striking contrast between the wretched state of the poor and lonely in the deep of winter and the genuine happiness that can be reached even through such hardship if you get your priorities straight; narratively, it doesn't really have anything to do with Jesus' birthday.
Kierkegaard and Kant, OTOH, are explicitly Christian philosophers that have had a huge influence on modern thought, but the Christian churches do not, to my knowledge, consider them divinely inspired. Why not Kant if we're going to canonize Paul?
Sainthood, prophecy, divine inspiration... That's the supernatural. I think that's all there is to it. The virtuous mundane don't get sainted. If they did, the Vatican wouldn't have time for anything else. (Which might be a good thing, come to think of it.)
That said, leave it to Thomas Aquinas to mess up my equation. The man was sainted for his philosophical writings, without a single traditional miracle to his name. We might think he was admired for his mind's work alone, and so in that regard it's only fair to do the same for more recent Christian philosophers.
However, Tom wanted to join the Dominicans at age 19, and though it didn't exactly work out as he planned at that time he basically spent his life studying and teaching and
generating theology on Dominican appointment. On the other hand, the medieval clergy revered Aristotle, but he was a pagan. Kierkegaard publicly criticized the Church of Denmark and wrote that the human race had outgrown Christianity. Kant said that the supernatural element of Christianity is superfluous. Organized church doesn't take well to dissent, and it exerts its influence largely by way of its claims to the supernatural. Of course they're not gonna put these guys on a pedestal. They're not considered ideal examples to be followed.
To the individual truth-seeking Christian though? These guys are great. That's beyond question. Approaching spirituality and ethics through reason? Yes! Fuck yes!
Booyah!And yeah, Bongo's got a finger on a big issue at hand here. Once you say that there is Christianity the philosophy and Christianity the religion, do you label things as Christian when they have one, or the other, or both? And even then, if we limit ourselves to what we all agree are Christian elements, we don't address the problem of, say, people who would rather see a mother die with her child rather than perform a life-saving abortion, but also claim to be Christians despite how Jesus probably would have improvised a weapon and gave 'em a good whack upside the head had he been present when the decision was taken. Err, well,
physically present, in any case.