Any believer would do well to critically consider their motivations for reading other works prior to undertaking such an action. Is it idle interest, waywardness, boredom, pride? A burden? Equipping?
I have read the Quran (I think fully once) when I was basically at an impasse with scripture and I had always wanted to be well versed in other texts as well, but it ended up speaking to me about 10% of the time (interestingly
@Roughsoul1991 mentioned a similar take away). Mostly it just felt human. Same thing with the apocrypha (of which I've only casually read the portions in catholic bibles). The apocrypha didn't speak to me at all...although I do find Maccabees (and the history) worth bearing in mind.
Basically it was during a period where I wanted to dabble and expected certain things to unfold...which they didn't anymore than they usually would in a state of unwisely unbridled curiosity.
There is only one "illumination" in the Quran that broadened my understanding of the enemy, that was one of my main reasons for reading it. It only confirmed that another name for the enemy was somehow in my mind, I liked how it sounded and I made a song about it with the "under pressure" instrumental track. When I realized whom it was another name for I was sincerely surprised, and I no longer do such things blithely.
An interesting verse somewhat connected to the above is that essentially all games of chance (dicing) are a creation of the enemy. True or not, I typically feel that gambling is wasteful and trying to figure out what chance is, nearly impossible. This somewhat factors into my "lot casting" understanding and what it is for. Much like almost all things the Lord can supersede a system and operate within it if he so chooses. Anything that goes directly against his character not included.
I've also read works by known enemies of the Christianity because at the time I felt destined to do so. There wasn't anything new in it as far as I could tell, but it did explain a whole doctrine that I was pretty sure contradicted scripture but I couldn't find anyone that knew anything about what was consistently brought to my attention (before reading). Essentially the pyramid system (scheme) of the mystery religion.
I currently don't believe in destiny and am back to my lifelong approach (barring a small window at a particular time in my life) that basically, if the Lord places a burden on your heart specifically, then he will equip you and it may contain understanding other works according to the letter. If not, scripture is sufficient for our task under the sun. Idle interest I discourage. At least have some sort of thought process other than a whim.