Before introducing the world to The Chronicles of Narnia, Lewis published Miraclesin 1947. It was his last straightforward defense of the gospel. Lewis told his friend and biographer George Sayer that he would never again write another "book of that sort." And he didn't. From that point forward he published primarily fictional, devotional, and biographical material. His passion for explaining and defending the Christian faith could now best be found in a magical world of talking animals.
That's why when Carl Henry asked him to write articles on topics of Christian doctrine, he had to decline. As Lewis told Henry, "My thought and talent (such as they are) now flow in different, though I trust not less Christian, channels, and I do not think I am at all likely to write more directly theological pieces. The last work of that sort which I attempted had to be abandoned. If I am now good for anything it is for catching the reader unawares - thro' fiction and symbol. I have done what I could in the way of frontal attacks, but I now feel quite sure those days are over."
One of the things evangelicals seem to feel obliged to do is to see theological points in everything. Everything has to be justified by a theory of justification, so to speak. Americans in particular can want there to be some "redemption" in the stories they embrace. The idea that a story could be about someone who doesn't find "redemption" (like the protagonist in John Woo's The Killer, or King Saul within the biblical narrative) or even a character like Wickus in District 9 who stumbles upon redemption without accepting some invitation, and this even amidst his various ethical failings, is not what evangelicals seem interested in. We want our redemption straight, no chaser. We want the unmediate 200 proof propositional statement, preferably explicated in the past-tense so there's no doubt who the redeemed one is. We may say we affirm an Augustinian approach to sanctification in American evangelicalism but in pop culture we seem to have more of a, how do we put this, Keswickian approach to the sanctification of somone in his or her character arc.
We can pay lip service to the idea of vocation but for cultural artifacts we may know but we don't care that it's possible to do things as Christians that don't have to announce at every single step "This was made by a Christian." I spent a few years over at Mars Hill and while some folks can talk about going "upstream" where culture gets made it remains to be seen whether or not that infiltration project has worked out or that it even needs to be consciously undertaken by a group of people gathered together under 501(c)3 status for that to be accomplished. After all, if you just do your job you're not actually going to change the world unless your job happens to be changing the world.
Suppose, for the sake of making a polemical point, the essential difficulty of evangelicalism is we've wanted to do the direct propositional hour-plus sermon about things. The writerly axiom is that you show rather than tell and evangelicals want to tell, tell, tell all the time. A skilled writer knows there is a time to tell and certain roles within the life of faith do, in fact, involve telling things but there's also the showing part and that may be where we have a lot of people who only know how to tell and haven't managed the showing part. It is funny that even within the art of writing there is an axiom to show rather than tell. How do you tell in a way that shows and in the visual media how do you show in a way that tells? That many people opt not to bother with these questions does not mean the questions don't get answers.
If many of today's evangelicals had gotten what they wanted they'd have gotten a Lewis who wrote more variations on Mere Christianity and never wrote any fiction. How obvious is the doctrine of justification by faith alone in the narrative of Samuel-Kings? I'm not saying it isn't in there, I'm just pointing out that in the narrative literature even the Bible itself seems to completely fail the propositional statement approach to doctrine that many evangelicals have wanted for how Christians write about Christian belief.