"Our problem in America is that we don't want to look bad. What God wants to do is to cause the ugly and the misshapen things in this world to confound the wise. If you reject that, you are actually rejecting the calling of God. Don't give excuses by saying, "No, I'm just not good enough." That is not humility; that is pride. You have to be willing to be held up by God, and look as foolish as you are. God would rather use someone whose misshapen flesh is held up by Him in humility, than someone who is really good at things but the goodness that they have is shallow; the more you get to know them, the more disappointed you are in their life. The anger of the Lord was kindled against Moses because Moses rejected the humble way. God allowed Aaron to speak on Moses' behalf, and this led to the separation of words and the Being of God. We have silver tongue orators who lack substance. The substance of God makes the mountains melt. A silver tongue doesn't cause anything to melt.
"When God is with us, we, in our flesh, are still lousy. But God will hold our flesh up, so that people will believe. Only the Holy Spirit, not our mouth, skill or brilliance can cause belief to come. He doesn't need you to be that good. He will just pop out of you. Does He pop out of you? He only pops out of a dead person, a staff thrown to the ground. You will make mistakes. You will not be that glorious in the flesh. It will be just you. But God will pop out of you and stand in front of you. He holds up our flagging flesh. Forget about trying to look better. God's power is predicated upon a barren womb. God doesn't say he will make you look good, He says, "I will be with you."
-Pastor Michael Koh preaches on Exodus 4...
Exodus 4:10-14 - "But Moses said to the Lord, “Oh, my Lord, I am not eloquent, either in the past or since you have spoken to your servant, but I am slow of speech and of tongue.” Then the Lord said to him, “Who has made man's mouth? Who makes him mute, or deaf, or seeing, or blind? Is it not I, the Lord? Now therefore go, and I will be with your mouth and teach you what you shall speak.” But he said, “Oh, my Lord, please send someone else.” Then the anger of the Lord was kindled against Moses..."