A few years ago I was browsing the bookstall at a Christian event. 'Any good new fiction titles?' I innocently asked. An older woman standing next to me visibly bristled. 'Why would you want to waste your time reading what's not true?' she demanded. I did manage a muddled defence but the question has stayed with me, especially since over the past few years I've been trying my hand at writing it as well as reading it.

On the face of it, it's a reasonable question. By its very nature Christianity has always had a commitment to the truth and fiction is very obviously not 'true' in the strictest sense. Jesus said he was (and is) the way, the truth and the life. John told his readers that his account was written 'so that you may believe' (Jn 20:31) – the implication being, 'because I've carefully researched it and found it to be true'. Paul makes the point that if Jesus did not truly rise from the dead then 'we are of all men most to be pitied' (1 Cor 15:19). So it's not good enough that the gospel should be inspiring, comforting or encouraging. We stand and fall by whether it's actually, verifiably, factually and literally true.

So where does that leave fiction and my friend who thought I was wasting my time?

As a literary form, the novel is quite a modern invention. The prize for the first European novel, usually goes to Don Quijote by Miguel Cervantes (in Spanish) (1605) and in English to Robinson Crusoe by Daniel Defoe (1719) - although some would argue for Pilgrim's Progress (1678). (Interestingly, for those opposed to 'Christian fiction', both Robinson Crusoe and Pilgrim's Progress are undeniably Christian works of the imagination.)

Thereafter the novel developed quite rapidly. Only 75 years after Robinson Crusoe, we get Jane Austen's first novel, Lady Susan, then about 25 years later Pride and Prejudice. After that the rest is history and nowadays you simply can't move for novels in every possible style and form.

And far as 'Christian' fiction is concerned, after an initial flurry, it arrives quite late to the party. Jane Austen and her contemporaries may not have been writing with a specific Christian purpose, but they were certainly working from a Christian world view. Her characters go to church; vicars, curates and parsons abound (often quite foolish and vain) and everyone is a member of the Church of England. Then we missed the bus. The nineteenth and early twentieth centuries saw a torrent of Christian non-fiction, exhorting, expounding and explaining, but while the novel was developing elsewhere in leaps and bounds, with a few exceptions, fiction explicitly expressing a Christian viewpoint was fairly thin on the ground. So if I'd been visiting a Christian bookstall any time up to about forty years ago and asked for fiction I would simply have got a blank expression in return.

Now fast forward into modern publishing. Representative of how things have changed, 1995 saw the beginning of the phenomenon that is Left Behind. Tim LaHaye and Jerry B. Jenkins' almost never ending series set after the rapture but before the second coming has sold in truckloads - over 65 million in fact (quite a lot of trucks) - spent more time in the New York Times Bestseller Lists than I've been in long trousers and has even wooed Hollywood with an action adventure thriller starring Nicolas Cage. Mark Kuyper, president of the Evangelical Christian Publishers Association (in the US) has said 'In many ways this series established Christian fiction as a significant category in publishing in general.' Jerry Falwell has said of the original title book: 'In terms of its impact on Christianity, it's probably greater than that of any other book in modern times, outside the Bible.'

After that have come a mountain of subsequent series, heroes, heroines and plots including Christian detectives, plucky (and godly) heroines, powerful pastors, fictionalised reworkings of Biblical stories and even glimpses into the spiritual underworld. More recently, in the interests of fiction guaranteed to offend nobody, almost every Christian publisher in the US (of which there are many) now has a range known collectively as 'bonnet fiction' - so called because the heroine on the cover wears a bonnet. This includes adventures in the Amish community, valiant setters on the frontier and southern belles with unsuitable romances. The common factor seems to be an age where sex and swearing hadn't yet been invented.

You may have already guessed that all this sounds very American despite the British roots of the novel and you'd be right. Although you could argue that in the Chronicles of Narnia we have the ultimate jewel in the crown of Christian writing, until fairly recently adult fiction with a Christian flavour was almost entirely produced in the land of the free and exported to these less dramatic shores. But now things are changing even here. Within the last few years Lion and SPCK, both venerable and thoroughly respectable publishers of Christian non-fiction have taken the plunge and now have reasonably extensive fiction lists.

So what's going on, why is Christian fiction on the up, what is it anyway and was my friend right that reading 'what's not true' is a total waste or time?

Maybe firstly we have to be a bit clearer on what we mean by 'what's not true'. Nobody claims that the characters in any novel, Christian or otherwise, actually did and said what the author has them doing and saying. For a kickoff it's probably much too unlikely that the events in a novel would happen to anybody, nevertheless, for the sake of a story, we suspend disbelief, accept that it is as the author tells us and read on to find out what happened next. It's fiction. It isn't true and nobody pretends it is.

On the other hand, if a fictional character or event is too unlikely, ridiculous or inconsistent then the author loses our attention as we instinctively feel 'she would never say that' or 'that's just too much of a coincidence'. So in some sense, fiction has to be true to life if not true to specific events. We root for Bilbo and Frodo because we have all felt what it's like to be the little guy faced with events that seem way beyond our ability. Yossarian in Joseph Heller's Catch-22 works because we've all been faced with incomprehensible bureaucracy and the feeling of impending doom. The Lord of the Flies connects because we are sadly all aware of the capacity for violence and cruelty in the human heart.

Contrast this with the fact that many celebrity autobiographies, conspiracy theories and diet and health books seem to be - to say the least - a bit fast and loose with the truth. Then we find the situation is not quite as straightforward as it seemed to start with. Fiction has to be 'true to life' but what purports to be 'true', can sometimes turn out to be fairly unconnected with reality.

Next up in evaluating fiction, maybe as with everything, we ought to ask 'what did Jesus do?'. While claiming to be the truth, it appears that Jesus also told stories that weren't 'true' in a literal sense. Luke 10:30 records the story about 'a certain man who went down from Jerusalem to Jericho and fell among thieves'. Did his audience take this to be a true account as we might find on the evening news or did they understand it to be a representative story of what certainly might happen and probably had happened a hundred times before? So with the servants who were left with various talents to invest in Matt 25, the young man who went off to a far country and the woman looking for her lost coin both in Luke 15. These are stories - not literally 'true' - but true a hundred times over in human experience and accepted by the audience and readers ever since as such.

So back to 'Christian' fiction and another necessary question. If good fiction tells stories that are true to human experience (think of the naive idealism of The Prime of Miss Jean Brodie or the relentless thirst for revenge in Moby Dick), what, if anything, is distinctive about Christian fiction? Does it have to have Christian characters, promote the gospel, only tell positive stories, recommend a life of faith or include miracles and answers to prayer?

Speaking about Christian rock music, Larry Norman, acknowledged as the founder of the genre, made things very simple. When asked what Christian rock music was he simply replied, well, I'm a Christian and I play it so I guess it must be Christian. Maybe at one level Christian fiction is simply fiction written by Christians which embodies and expresses the values, priorities and world view of the followers of Jesus - whatever the specific content. Of course this also implies that themes directly counter to the gospel, like glorification of violence, misogyny or promotion of racism should have no place in anything that claims to speak for the Kingdom of God.

Then we also shouldn't lose sight of the obvious fact that God is creative. As if the universe itself isn't sufficient evidence of that we have the endless diversity of human nature and human creativity. In saying. 'Let us make mankind in our own image' (Gen 1:26) it would seem reasonable that God's own creativity should have been part of the mix. Many artists working in whichever medium say they paint, write or compose simply because they can't help it.

Besides of this the Bible is full of poetry, symbolism, prophetic images and comparisons and stories. While clearly not 'fiction', they are certainly creative uses of language. Then there are the parables which, as we've already seen, could be viewed as fiction of a sort.

So where are we up to so far? God is creative and so are we. Christianity is all about truth and not just facts that are true but deeper truths about human nature and our relationship to a creative God. Fiction, while not factually true excels at exploring what it's like to be human through stories that tell deeper truths. And finally, Jesus used representative stories in exactly this way, to point to underlying realities.

So maybe, in the light of all of the above, a Christian novel does not necessarily need to proselytise, convince or be full of Bible references but should aim to be true to both the good and the bad of human experience and behaviour and embody the way the universe is both as God created it and as it has subsequently become. Like the Bible itself, It needs to be serious about good and evil, love and hate and guilt, forgiveness and redemption because these are what the gospel is about.

And guess what? These turn out to be the most fundamental, perennial themes that almost all serious literature and movies deal with, regardless of world view. The Great Gatsby is about arrogance, excess and pride. Dr. Jekyll and Mr. Hyde is about the uncomfortable co-habitation of good and evil in each one of us. Les Miserables is about the redeeming power of grace and forgiveness. Etc. etc.

So back again to my adamant friend. Am I wasting my time reading 'what's not true' or is there a bit more to it than that? Well, at one level, we all love stories simply for the excitement, suspense and resolution they embody so as pure entertainment there's nothing wrong with that - whether or not it actually happened.

But at a deeper level, telling stories that exemplify deeper truths is not only a perennial aspect of human creativity - Christian or not - but is a practice Jesus employed and Christian writers today continue. We believe that God had revealed a deeper understanding of human nature and how we got this way and it seems only reasonable to tell stories that explore some aspects of that. If that makes people of like faith, other faith or no faith think a bit more about what it all means then all to the good.

Les Cowan is author the David Hidalgo series of thrillers the first of which, Benefit of the Doubt, is due to be published by Lion Fiction in June 2017. More at www.worldofdavidhidalgo.com