If you grew up in Sunday School, you probably know the story of Moses at the burning bush. You can look it up in Exodus, chapters 3 and 4. Many have inferred from the way it reads that Moses had, or at least felt that he had, some level of speech impediment. It has also been suggested that he simply refers to the fact that he had not used the Egyptian language in forty years.
The message is the same in either case. No kind of impediment can stand in the way of Yahweh. When God has overcome each of his prior objections, he comes to this one. Was it the root of his fear all along? We are not told. What we are told is that God finally becomes angry with Moses.
And Moses said to Yahweh, “Please, Lord, I am not a man of words, neither recently nor in the past nor since your speaking to your servant, because I am heavy of mouth and of tongue.” And Yahweh said to him, “Who gave a mouth to humankind, or who makes mute or deaf or sighted or blind? Is it not I, Yahweh? So then go, and I myself will be with your mouth, and I will teach you what you must speak.” And he said, “Please, Lord, do send anyone else whom you wish to send.” And Yahweh was angry with Moses and said, “Is there not Aaron your brother the Levite? I know that he certainly can speak, and also there he is coming out to meet you, and when he sees you, he will rejoice in his heart. And you will speak to him, and you will put words in his mouth, and I myself will be with your mouth and with his mouth, and I will teach you what you must do. And he will speak for you to the people, and then he will be to you as a mouth, and you will be to him as a god.
Exodus 4:10-16 Lexham English Bible
This is pure speculation, but I wonder if Yahweh would have established the Levitical priesthood through Moses rather than Aaron if it had not been for Moses’ reluctance to do what He asked. What we can definitely learn from this is that when God calls us, we should answer without hesitation. Whatever the challenge you are facing, He is able to overcome it. If He has given you a mission, don’t delay in carrying it out.
You might say that He has never spoken to you in a burning bush or in any discernible way for that matter. I do believe that we should be in the kind of relationship with God that involves some level of discernible communication. I believe that we cannot be very effective without it. Having said that, we already have His written word. Start there, and as you meditate on His word, you will find His Holy Spirit guiding you. Act on what you find there. Don’t let your shortcomings, real or perceived, get in the way. God says to Paul, “My grace is sufficient for you, for power is perfected in weakness.” (2 Corinthians 12:9 NASB)