Tolkien’s pseudo-medieval, philologically constructed fantasy epic The Lord of the Rings has broadly become the standard referent in people’s minds of medieval culture—of what those people who once inhabited the castles, churches, and walled towns that ornament much of England and the Continent were perhaps vaguely like. One important effect of this Tolkienesque Middle Ages to which I can attest both from personal experience and from my work in the classroom is the absence of religion from popular notions of medieval culture. Typically, American students understand the Middle Ages as a period that valued individual honor, nobility, heroism, and violence—that is, chivalric culture—but they have difficulty integrating the deep corporate religiosity of the era into this same understanding. Of course Tolkien was not the first to eschew religion in a tale of medieval fantasy—Walter Scott, Mark Twain, and Robert E. Howard are but a few of his many notable forerunners in this regard. But Tolkien’s increasing influence over the last forty years in a variety of media has done much to secure this popular idea of a chivalric, impassioned, but essentially secular Middle Ages. [Courtney M. Booker, ‘Btye-Sized Middle Ages: Tolkien, Film and the Digital Imagination’]
There's something very striking in this notion; Booker is surely right. Tolkien left religion out of his world for good aesthetic reasons; but this lack has now been read back into the world itself, or the historical world, as a kind of reverse-mimesis.