The question is really "what is the source of inspiration for ALL artists?" For me, the simple and straightforward answer is the Spirit of God...I think for non-believers though, the answer may be harder to comprehend. It seems to me that a major reason humans are inspired to create is that we were ourselves created. Sort of a round-about way of saying that God made us and intended that we would not only procreate but also create - goods, clothes, tools, homes, boats, paintings and stories. Unfortunately, we've also created our own gods, too.
It also struck me that God's preferred method of communication is the Word. Not to get into any discussion over graphe (written word) versus logos (wisdom/truth/etc)...but certainly the symbolism of Jesus as the Word is inescapable. Yes, God has communicated directly through the spoken word to many in history, but it is interesting that God then wrote it down. Certainly Moses could have remembered ten little rules and repeated them to the Israelites. But shortly thereafter, the Ten Commandments would have been something like this: 1. All paths lead to God so worship whatever god you want. 2. Idols are only a visible representation of an idea, so it's okay to bow down and worship them. 3. It's okay to use My Name in vain, I really didn't mean this one....
You get the point. God thought the Testimony so important that He inscribed the precious words Himself. And when Moses broke the first set, God kindly inscribed a second set as well. And does Scripture ever say that only the Ten Commandments were inscribed on the tablets? They were covered front and back per Exodus 32:15, and if you've ever seen an ancient potsherd or scroll, they could get an enormous amount of words in very small spaces!
God clearly values the written word. Words are indeed powerful, even in fiction. I never really thought "Christian fiction" was anything more than entertainment until I was doing the hair of another teenaged girl in my daughter's show choir. I was only half-listening to the general babble and banter until she told another girl to read Francine Rivers' books. Then she said, "I always supported abortion until I read Redeeming Love." Okay, I got the point then.
So write, because it's what we are supposed to do. "The unfolding of your words gives light; it gives understanding to the simple." Ps. 119:130
And my our words always do just that.