I don’t remember where I came upon this fact; I suspect it was over at Steve Runge’s blog, but I can’t remember for sure. The observation is that in Greek, the “normal” (or unmarked to use a linguistics term) past tense [*] [**] verb varies depending on genre. If the genre is narrative (like the Gospels), then the imperfect is the normal tense chosen. In other genres (like epistles or commentaries), the aorist is the default (or unmarked) form.
All I can say is that this has been hugely reinforced over the past several months of my reading. My reading has been almost exclusively genres that heavily use the aorist: commentaries, letters, and psalms. I recognize the aorist readily, but the imperfect still often throws me for loops. For a while, I had honestly forgotten that there was such a thing as the imperfect! However, I have recently started noticing the imperfect more. For example, during a commentary on one of the Psalms, Eusebius might retell a story from David’s life to explain something In such cases, the imperfect invariably becomes prominent.
So, I guess all of that goes to say, I’ve found this linguistic/grammatical distinction to be helpful!
[*] I know “tense” may not be the most correct work, and that there are lots of debates on aspect versus tense, but since tense seems pretty linked to morphology, I think it serves pretty well here. If anyone has the better term, please pony up!
[**] I’m also aware that Greek verbs aren’t quite as tied to time as English verbs are, but since the imperfect and aorist are typically used to describe events that occurred in the past, I’ll use the term “past tense,” even if haphazardly.