I've read a number* of Christian personal narratives recently, so I feel very qualified to opine in a very general way about how Christian intellectuals think and write. The books were The Imitation of Christ by Thomas a Kempis, The Confessions of St. Augustine, and Mere Christianity by C.S. Lewis.
And what I find fascinating about all these books is that they start off from feelings. Kempis obviously has a very intense sense of himself as a sinful being. St. Augustine feels intuitively that there is a life beyond, but he's very troubled by the presence of evil in the world. And C.S. Lewis feels that the life of the world can't be fully satisfying to any human being. Notice, these peoples' feelings are not the same. The world is so often boiled down to one spiritual problem: "Where did this all come from?" or "What is the meaning of life?" But there's actually so much more than that. At every level, every day, every moment, we're confronted by paradoxes.
(For instance, I know that achieving success as a writer won't make me happier than I am now, but I nevertheless feel compelled to pursue it with an unusual amount of vigor.)
So yeah, there are a lot of spiritual problems that it is possible for a person to have. But these three men, for various reasons, find their solutions in the same place: accepting Jesus Christ as their Lord and Savior.
And that's where the fun part begins!
Because then each of them, in their own way, has to defend Christianity and its theology. Of them, Kempis probably has the easiest task, since he lived in a time and place when Christian faith wasn't particularly under attack. But even he devotes the last book of his work to writing about the place of the Sacraments in the life of Christian contemplation.
St. Augustine is a fascinating case, because his route to Christianity is obviously very intellectual. Throughout the book, he seems almost predisposed to Christianity, but he's held back by the problem of evil: if God is all-powerful, then how can evil exist? He's attracted to an alternate faith, Manicheism, precisely because it offers an elegant solution to this problem (it says that the world is locked in conflict between two countervailing forces--a good one and an evil one. Basically, in Manicheism, God is not all-powerful). However, there's something about this that doesn't feel intuitively right to Augustine. It's a sensible theology, but it's not a comforting one. Augustine wants to live in a world that is controlled by an all-powerful God.
Anyway, he eventually sorts it all out and becomes satisfied with the Christian faith.
C.S. Lewis has different concerns. In fact, he disposes of the problem of evil in a way that seems almost antithetical to Augustine. He claims that the Earth is literally under the control of the Devil. Like, the actual Devil--Lucifer. He calls the earth "enemy-occupied territory." Which seems a bit unsophisticated to me, since I am used to a more high-brow Christianity...but actually it makes a lot of sense. There's of course some rigamarole in there about why God can't just come in and sweep away the Devil (it has to do with free will). And it falls apart if you want it to, but it also holds together if you want it to.
That's the fascinating thing about religion. Lots of people are happy with a religion that has a minimum of content: a generalized spirituality. But for a lot of people that doesn't suffice. They want answers. Theology seems, to many people, like an unnecessary trapping. But, to me, it actually seems highly necessary. Theology is the contortions you put religion through in order to make it fit the world.
In reading these books, the contortions are sometimes so naked and so obvious that I was reminded of William James and his philosophy, Pragmatism. William James was basically all like, "We should just believe whatever works for us."
(His Varieties of Religious Experience is still one of the best books I've ever read).
And you can see, particularly in the case of St. Augustine and Lewis, the ways in which they're searching for a theology that is both comforting, logical, and feels intuitively true. And they found it (yay!)
*Hey, three is definitely a number.