The only modern Christian writers I can take in large doses are G. K. Chesterton, Hillaire Belloc, and the Inklings: Dorothy L. Sayers, C. S. Lewis, and especially Charles Williams (I don't know Tolkein and am not a fan of long novels). I'm not saying that the more recent Christian writers aren't good--I simply don't know them. Charles Williams (there are two writers with that name--be careful) is in my view the most revelatory.