Creative Christians enjoy looking for new ways to express old truths. In our zeal we try Looking for God in Harry Potter, Finding God in the Lord of the Rings, and even examining The Gospel according to Dr. Seuss. Exploring Christian themes in literature is all well and good. The problem comes when we rip these themes out of their proper context. Like the child who licks the frosting off the Mini-Wheat and throws the rest away, we're far more delighted to discuss the themes we've discovered than the story itself. But the message was not meant to exist apart from the story any more than the heart was meant to function apart from the body.
"The gospel itself may be made harsh by precepts void of warm narrative. In spite of the fact that the Bible is filled with parables and stories, our zeal to evangelize and to encounter secular cultures with moral reform has shackled evangelicals to deadening presuppositions. The presuppositions do not kill because they are false (they are indeed true) but because they strip away mystery and process — the very ingredients of a good story."
I like Calvin Miller's idea of mystery and process. A good story does not simply provide us with a cold precept—"do not commit adultery." A story gives us a world to explore an idea in, room to experience its mystery, and time to process it. Good stories show far more than they tell. They provide us with an experience of truth. We don't read about grace in The Idiot, we have an encounter with it in the person of Prince Myshkin.
Many Christian writers write their books in reverse. By that I mean, the writer will think of a theme or truth that he or she wants to communicate. Then that author will write a story based on that theme. The characters, plot, and setting all exist to allow the writer to communicate an agenda. This method has things backwards. The message should not give birth to the story. The story gives birth to the message. C.S. Lewis explains how he wrote The Lion, the Witch, and the Wardrobe.
"Some people seem to think I began by asking myself how I could say something about Christianity to children…. I couldn't write in that way at all. Everything began with images; a faun carrying an umbrella, a queen on a sledge, a magnificent lion. At first there wasn't even anything Christian about them; that element pushed in of its own accord."
One reason, among others, why I believe The Shack will fail to become a classic is because it feels as though the writer had an agenda in mind and then set out to create a story around it.
So what makes books such as The Scarlet Letter, Anna Karenina, The Idiot, The Divine Comedy, Gilead, Till We Have Faces, and A Tale of Two Cities so good? What makes a book a classic? First, as we've discussed, the authors have made the story primary and the message/theme secondary in each of these novels. The authors show us the truth rather than beating us over the head with it. Second, each of the authors displays a mastery of the craft of writing in their work. Poorly written novels rarely hang around very long. Like a new penny in a dung heap, the best of messages will not shine out of shoddy prose. Third, these classic authors displayed an unusual degree of psychological insight and produced vibrant, believable, enduring characters. Because of this we can see ourselves or people we know in their characters. This helps to produce a bond between the reader, the book, and its characters. Fourth, these novels possess universal elements which transcend their time and culture. They still have the power to speak to us and resonate with us today. Fifth, and finally, these writers, as Shakespeare said, spoke what they felt not what they ought to say. That is, they were honest. They described life as they saw it not as they would have liked it to be.
 Calvin Miller, "Hope in a Doubtful Age" in More Than Words, (Grand Rapids: Baker Books, 2002) 258.
 Penelope J. Stokes says, "One of the greatest temptations for Christian writers is to have a preconceived idea of what great spiritual truths our readers should glean from the work. We desperately want them to understand, and so we set up neon road markers to point the way to the religious 'themes' of the novel. 'Get it?' we shout. 'This is the way a Christian is supposed to live!
"But the purpose of fiction is not to teach a lesson, preach a sermon, convey the message of salvation or set up guidelines for Christlike living. The purpose of fiction is to tell a story. The purpose of reading fiction is to be immersed in the lives and experiences of the characters. Any spiritual insights that take place in the reader happen subliminally, not overtly."
Penelope J. Stokes, The Complete Guide to Writing & Selling the Christian Novel, (Cincinnati: Writers Digest Books, 1998) 82.
 Lyle W. Dorsett and Marjorie Lamp Mead, editors C.S. Lewis Letters to Children, (New York: Simon and Schuster, 1985) 6.
 This is by no means a comprehensive or exhaustive list of what makes a book a classic. It merely shows several key elements.
 Philip Yancey says, "When I began writing openly about my faith, I concluded that I had only one thing to offer: honesty. I had heard enough church propaganda growing up. I would cling to the stance of a pilgrim, not a propagandist, describing life with God as it actually plays out, not as it is supposed to play out." Philip Yancey, Soul Survivor, (New York: Doubleday, 2001) p.270.