Bible Verses About Preaching: Moses, slow of speech

“Please, Lord,” Moses replied, “I have never been eloquent, neither in the past nor since You have spoken to Your servant, for I am slow of speech and tongue.”

And the LORD said to him, “Who gave man his mouth? Or who makes the mute or the deaf, the sighted or the blind? Is it not I, the LORD?

Now go! I will help you as you speak, and I will teach you what to say.”