I had an interesting conversation last night. Of course, it's likely that I wouldn't blog about one that wasn't.
My field of expertise is Early Christianity. I have observed that it's not really the case that Early Christians wrote fiction. Now, something of this can be argued and nit-picked over, but it is generally true. Of course, the lines between history and fiction are not all that distinct when it comes to some of this literature. In fact, perhaps the favourite Christian genre was and remains hagiography - saints' lives, and we can't exactly say that it all fits into the domain of strict history. Nevertheless, there seems to be a very pronounced preference for non-fiction with early Christians, almost an obsession with 'the truth.' Okay, now you are going to say that truth and fiction are not strictly opposed. Yes, a many great truths - perhaps the greater truths - are to be found in fiction. The strongest case and point, the parables of Jesus.
Philosophically speaking we need to think of two things. One, the Jewish influence, and this was strongly historically-minded. Secondly, the Greek, more specifically, the Greek Platonic vein, which was hugely influential on early Christianity. Such were not historically-minded, at least not in the 'modern' sense of the word, in fact, they devalued historical happenstance, the world of change; they were specifically interested in the eternal, changeless realm. So there is a mix of contrary influences here. Christians valued both. The Incarnation was an historical happenstance, but it was the revelation of the highest truth.
So why did it turn out that they weren't interested in fiction - was the Jewish aspect stronger? That suggests that the Platonists were interested in fiction. I think they were, but in that particularly Christianly acceptable kind called allegory, of which Plato gives many examples. This was the first kind of fiction to arise in the Christian sphere - I am thinking here (as was suggested to me last night) of Boethius's Consolation of Philosophy (6th century), which but the first of a million like works. Were the Chansons de Geste the first instances of true Christian fiction? What makes them specifically Christian? Nothing, it seems to me. Specifically Christian, the allegories, Piers the Ploughman etc., and, of course, the Passion Plays. But again, a Passion play is not fiction and the allegories are not fiction for their own sake. They are hyper realistic.
So where does this leave us, this 1200-year tour of Christian history? Some early Christian loved poetry. But poetry is not fiction by definition, but can be about anything basically, just as long as it is lyrically beautiful. But the early Christian poetry, like that of Augustine's friend, Paulinus of Nola, or Gregory of Nazianzen and Ephrem the Syrian were not fictional, because that smacked too much of paganism.
It has been observed that the more pious the Christian the worse his fictional art. The great exception to the rule always cited is Dostoevsky. I'm no expert. I don't like fictional literature that much -why? Because I'm a great Christian? That's the question, isn't it?
(To read about Christian poetry from the Patristic era, you could start with vol. 4, section 5 of Quaesten's Patrology.)
Again, I have no expertise in literature. I just know the Early Church, and I know that they didn't like fiction per se.