“Look, I am unskilled and inept in speech; how then will Pharaoh listen to me and pay attention to what I say?” There is a major flaw in our thought process when we, like Moses, believe that the impact of our words lies in our ability. It doesn't lie in our ability to choose the best phrasing. It doesn't lie in our ability to use perfect grammar or even to spell words correctly. It doesn't lie in our ability to weave a dramatic and compelling story.
As a writer, I desire those abilities - I'm attending Blue Ridge Mountain Christian Writers Conference next week to continue to learn to do all those things better (as well as marketing, character development, networking, etc). But the real impact of our words lies in God's Spirit speaking through us to soften hearts to hear the words, to place our words in the context of someone's life experience in such a way that they are drawn to Him. No amount of studying or preparing or learning or practicing would allow me to do that.
"Look, I am unskilled and inept in writing; how then will people read my words and come to know Christ?" The answer is through the mighty working of the Holy Spirit in their hearts. If anything I write touches a heart and draws it closer to God, that is His Spirit at work.