Following my dearly beloved Rumer Godden, below, there is another writer fascinated with faith, and especially the Catholic faith: Taylor Caldwell. She wrote a billion novels, many of which are very thick, lots and lots of story there, and are of the more-or-less-historically-accurate genre: she seems awfully sure of the motivations of the actual people she writes about, but at least her Regency duchesses don't make telephone calls. Her best-known novel is probably Captains and the Kings, a saga that strongly resembles the Kennedy family.
She wrote a couple of books about St. Paul (which I just realize that I never read, oh, boy!) and Judas Iscariot, as well as one I loved as a teenager: Dear and Glorious Physician, about St. Luke. But the book that I've read until the covers have fallen off my paperback, as a dependable getter-to-sleep, is Grandmother and the Priests, written in 1963. (The link is for a bunch of amateur reviews of books and movies. Scroll down to find the one for this book. It's quite good.)
In the early 20th century, Irish and Scottish priests gather at the lavish dinner table and fireside of the narrator's grandmother, a demanding, independent, bejewelled pistol of a woman. She feeds and funds them, but won't hear of the state of her soul, and extends both generosity and snubs to her granddaughter as well. The narrator and her grandmother are not the meat of the novel, though; that's contained in the eleven stories of heroic priests, splendid and funny sagas of bravery large and small. These stories are set in an Ireland reeling after the Famine and deserted by her starving children for America, and in Scotland, suspicious of Catholics and also poverty-stricken. The Devil is met and bargained with, true lovers are united, dogs communicate their master's anguish and a murder mystery is solved. But these stories are not fanciful. They are completely believable. They are frankly and unabashedly legends. Fr. Benedict Groeschel says that a "legend is something that may or may not have happened, but is true anyway."
Miss Caldwell seems to have some real understanding of being touched by God in the middle of our everyday lives. In Dear and Glorious Physician, she writes a moving description of the pagan Roman Luke being drawn by love and awe to a temple of a god unknown to him, a temple with a cross. (Now that I think of it, the timing of his youth and his discovery of the truth of Jesus Christ might be a little off.) Likewise in Grandmother and the Priests, one chapter is about a priest who loses his faith right in the middle of Mass, and how he finds it again in the depths of his despair (I cry every darn time). She seems to understand how God reaches out and touches us, perhaps leading first with an earthly thing, but bringing the weight of His Love behind it to convince us of His Presence.
I love Miss Caldwell and Miss Godden's books. They are novels, nice non-challenging airport reads. You don't have to have a reference book handy. You aren't embarassed by what you don't know. It's a shame that you may have to find them in a library or on eBay, rather than in current print.
I'm a little afraid of Flannery O'Connor, her mysticism and I don't quite resonate, probably due to my own sinfulness. I'm more uncomfortable with Evelyn Waugh, who is tortured by his faith. God bless G. K. Chesterton, I read the Fr. Brown books and I'll read them again, but they can be a little arduous. I'll give all them a periodic retrial, but I'll regularly reach back and tip a Godden or a Caldwell off the shelf when I want to enjoy a nice, resounding, Catholic read.
Next: Theophilus North, by Thornton Wilder. Not deliberately Catholic, but that man was swishing more than one toe in the Tiber, at least in his view of the beautiful holiness and complexity of God's Creation and the holiness of our time spent in it, before Heaven.