Those who would defend the genre(s) of Christian fiction sometimes seem peculiarly committed to muddying the water around any definition what Christian fiction is.
It's almost as if the only way they think they can defend it is by causing some confusion, and by obscuring any understanding of what it is.
The only clear way I know to talk about it, and talk about what we mean to be talking about "Christian fiction," is to talk about Christian fiction as a genre or a series of genres, and as a market. So: Christian fiction is what is sold on the Christian fiction market, which is determined by the things that determine the shapes of markets, and Christian fiction is marked by conventions of genre that make it distinguishable from other, similar fiction.
The advantage of this is that it's clear and fairly easy to decide what is and isn't Christian fiction. It's an empirical claim. And can be explained in materialist terms, without recourse to normative definitions and reified ideas. It has the flexibility the market has, so when the market shifts (e.g., when Christian fiction is no longer only sold in Christian bookstores) and what's marked as "Christian fiction" in a given context or culture shifts (e.g., when Christian fiction is no longer only Christian romance fiction), this definition is flexible enough to shift with it.
The disadvantage, I suppose, from the perspective of those who produce such works, is that the definition doesn't do any of the work of defending the Christian fiction as such.
It also doesn't offer or reenforce a normative claim. About the fiction or about Christians and Christianity.
Against this definition, (some) Christian fiction authors will often give definitions that are really arguments disguised as definitions, working as arguments, at least on some level, but making no sense at all as definitions of the category of fiction that's marked Christian.
The definitions I'm dissatisfied with (see here and here) are:
1. Christian fiction is fiction written by a Christian.
2. Christian fiction is fiction that evangelizes non-Christians or edifies Christians.
3. Christian fiction is fiction written from a Christian worldview.
4. Christian fiction is fiction that point to Christian truths.
I don't think any of these really work, and can think of cases of writers where each definition would have to get really contorted and weird. They all seem very insufficient, and have really basic problems.
1. How do you decide someone's a Christian (Joan Didion? John Milton?), what if they say they are but there work doesn't seem Christian (i.e. adhere to any genre conventions, e.g., Denis Johnson, James Ellroy, John Grisham), or what if they are at one point and then not at another (e.g. Anne Rice)?
2. Can't lots of things edify? Can lots of things push, lead, guide, and be used by God for conversion?
3. What do you mean "from"? How specific is "Christian worldview" supposed to be, and who decides what that is?
4. How specific is it going to have to be? "Points" as in points just to Jesus and the need for personal acceptance of Jesus (which will exclude lots of stuff sold as Christian fiction, including some classics, such as re-tellings of Old Testament stories) or such general things as the fallen state of the world, the need for redemption, salvation, etc. (which will include lots of stuff that's never sold as Christian fiction).
On the other hand, what's worse is the definitions that go so broad as to be basically meaningless. The prime case of this is John Mort's book, Christian Fiction: A Guide to the Genre.
It's meant as a "comprehensive guide," and is mostly lists of publishers who put out Christian fiction, lists of Christian awards, lists of notable works in a given sub-genre, lists of journals that keep track of Christian fiction publishing, and so on, and works as a reference guide for librarians, etc. To that purpose, the book's fine.
But Mort, in his lists, includes so many different sorts of novels, ignoring the markets in which they exist and including them only on the basis of a detection of a Christian theme or subject matter, he ends up talking about books that, really, no one meant to be talking about as "Christian fiction."
He calls Nathaniel Hawthorn's The Scarlet Letter "the first American Christian novel of any consequence," count's Stendahl's The Red and the Black as a classic of Christian fiction, includes Norman Mailer's The Gospel According to the Son under the list "Biblical Fiction," and writes he would be remiss to not include Sinclare Lewis' Elmer Gantry.
Mort also says things like, "The chief antecedent to Christian fiction is, of course, the Bible."
At which point I throw up my hands. How is this helpful?
Was this really what we were trying to talk about with "Christian fiction"?
We have to go back to the definition of market and genre.