I thought Dr Bob Godfrey (Westminster Seminary of California) had a great answer in this thought-provoking essay on their site. He is one of the bright theological lights of our day, and a name you should remember.
Here’s a taste of Dr Godfrey, quoting C S Lewis, to whet your appetite…
… Lewis argued that the value of reading literature was a way to experience many things that we would not otherwise experience. “We want to see with other eyes, imagine with other imaginations, to feel with other hearts, as well as with our own” (137). Lewis explains what it means to see with other eyes in these terms: “In reading imaginative work, I suggest, we should be much less concerned with altering our own opinions – though this of course is sometimes their effect – than with entering fully into the opinions, and therefore also the attitudes, feelings and total experience, of other men. Who in his ordinary senses would try to decide between the claims of materialism and theism by reading Lucretius and Dante? But who in his literary senses would not delightedly learn from them a great deal about what it is like to be a materialist or a theist?” (85-86). When we read well, we enter into new worlds: “A true lover of literature should be in one way like an honest examiner, who is prepared to give the highest marks to the telling, felicitous and well-documented exposition of views he dissents from or even abominates” (86).
Of course, I think the best fiction is “historical” fiction, which helps to accurately illumine another time and place for us (for example the series of novels by Patrick O’Brian).