"Faithful is he that calleth you, who also will do it." 1 Thessalonians 5:24
Our weaknesses become our excuses-- I am not educated enough; I am too shy; I am not popular; I am not talented and so on. Our excuses are usually true reasons-- we do have shortcomings and inabilities. But don't you think God already knows that? Don't you think He already knew Moses couldn't speak well when He called him? Sure, He did. He already knows you can't do it when He calls you to do it, but He calls you anyway because He uses "weak and foolish things".
When He called Moses, Moses wasn't able to do what He called him to do, but God could do it. When God calls us, we act like it is going to be us who does it. We act like it is all going to depend on us. We act like it is our abilities that will make it happen. That is not true. It is not us that does it-- it is not by our might or power but by His Spirit; it is the Spirit of your Father that speaks for you; it is the Father that does the work. We are only vessels that He does it through.
The truth of the matter is that when God calls us to do something, we can't do it. God knows that. But He can do it. And He will do it. All He ask from us is to trust Him and obey. Then He will do the rest. He will do whatever needs to be done. All Moses was was a vessel. He didn't part the Red Sea. He didn't turn the waters to blood. He didn't bring the plagues on Egypt. He didn't give manna in the wilderness or water from a rock. God did it all. All Moses did was yield to Him, trust Him, and obey what He told him to do. We start making excuses because we think that we are the ones who have to "make it happen". We don't. We can't! But if God calls you to do it, He can and will do it through you.
Have a great day. God knows you can't do what He calls you to do. But He can do it, and He will do it. You only have to trust Him and obey what He tells you.
For further reading:
1 Corinthians 1:26-28
Exodus 4:10
Acts 3:12,13
Zechariah 4:6