Sometimes God says 'Speak'

I am left with so much to process this day. Some of it is probably not mine to process. Regardless, my mind will not leave it be. Am I trying to work many things out in my head that don't need to be worked out?  I don't know if this is God's destraction from worldly things that would hinder me, or if it is a distraction from the enemy to keep me off balance in my spirit. I am more than annoyed at what I am seeing done by certain people who believe they are serving God. I see a spirit that is contrary to the Holy Spirit, at least that's what it feels like. 
Part of my mind says 'do not criticize people trying to serve God.' Part of my mind says 'do not step away from the voice of the Spirit within you.' So the prayer comes out of me: "God close my mouth when I should not speak. Open my mouth when I should and fill it with your words, not my own."
I am reminded of a time when my three oldest daughters were young. From my work spot in the kitchen, I heard one of my daughters screaming and yelling and stomping. She was known to be a fit thrower, and so I headed out. When I approached the back door the scene was very strange. My oldest daughter and youngest daughter were sitting on small chairs focused on the middle daughter who was screaming incoherently, stomping her feet, shaking all over, pacing back and forth and pointing her finger repeatedly at her sisters. As I came through the door to the porch, all three girls stopped and looked at me. Rhonda held up her hand toward me as if to motion 'stop' and said quietly "I was preaching." It was comical and yet, . . .
One of the things I realized is that if the Holy Spirit is not speaking through me, my words will eventually be incoherent or ineffective. If my speaking is to matter at all, it must not be me giving the impression of being a preacher. Sometimes God says 'open your mouth and speak', and I do and it's powerful. Sometimes God says 'no, not now'. Sometimes God says 'speak' and I do and then I keep speaking when it becomes my words and not his. It's like when Moses was told to speak to the Rock. He spoke but then he went on to rail on the people. Though what he said was true, it was not what God wanted him to say and he was condemned for not setting God apart in front of those people. Instead of allowing God to change the minds of the people with his ways, Moses tried to change their minds with his words and for that he was denied the right to lead the people into the Promised Land.
I think I used to see that as harsh, but what I am beginning to understand is that God must be followed explicitly through the Spirit, not the mind, if we are to speak his words. I have never asked to be God's spokesman. I love to study the Bible, I love to put words into sentences and paragraphs, but I do not think of myself as a preacher or a prophet. And yet sometimes God says 'speak'.