I've been doing the 'Read Through The Bible' plan and yesterday was reading Exodus 3 & 4. I recommend reading Exodus 3 & 4 to get the context. My major thought is around Moses response to God's call and then what God says in return.
God appears to Moses in the burning bush. God then tells Moses his plan to rescue his people. He specifically says, "I have come down to rescue them and to bring them up out of Egypt and into a good and spacious land. So now, go. I am sending you to Pharaoh to bring my people out of Egypt." (I cut some out)
But Moses said to God, "Who am I, that I should go to Pharaoh and bring the Israelites out of Egypt?"
And God said, "I will be with you. And this will be the sign to you that it is I who have sent you: When you have brought the people out of Egypt, you will worship God on this mountain."
Moses said to God, "Suppose I go to the Israelites and say to them, 'The God of your fathers has sent me to you and they ask me, 'What is his name?' then what shall I tell them?"
God said to Moses, " I AM WHO I AM. This is what you are to say to the Israelites 'I AM has sent me to you.'"
When we are called to an impossible task in our eyes, or one that we think is difficult and will require more of us than we think we can actually give, we ask, "Who am I? God, who am I that you would ask this of me? Pick someone else, someone who's better, who's stronger, who's holier, who's smarter, who's (fill the blank of your personal weakness) ." We think that when God actually sees who it is that He has just called, He will say, "Oh, you're right! I did mean to ask the other Jessica Rohrig - not you. How ridiculous of me!" Obviously, the God who sees and hears could easily mix us up with someone better suited for the job. We probably do need to help Him out in that regard.
Instead, how does He respond? He tells us that He will be with us - and not just that, He'll give us a sign that we can trust Him - that it really was the LORD who called us and not just some weird hallucination. But, on top of that, He says (in essence), "Do not worry about who you are - or even who you are not. The question, my dear one, is not 'Who are you?' The question is, 'Who am I?' When you ask, 'But, Lord, who am I to do this?' Remember that I AM the one who will do this."
The question, who am I? God answers by telling us to not to focus on us, but on Him. He who formed us knows that we are but dust. He knows our weaknesses and our imperfections - but, He is the one who has chosen the weak things of this world to shame the strong. He is the one who wants to display what He can do in a weak, but willing vessel to the watching world. He's not asking for us to turn in a stellar performance or to astound him with our abilities; He's asking for a willing and obedient heart to hear Him and to follow His leading and obey His call. That's all. The hard parts, the obstacles, our stubborn & sinful hearts, He'll take care of. He'll either move them or He'll make us stronger by working through us as we move them. He will be worshiped and glorified as the Lord of the Universe one day, but for right now, He simply wants us to make Him the Lord of our hearts and lives.