Then Moses said to the Lord, "O my Lord, I am not eloquent, neither before nor since You have spoken to Your servant; but I am slow of speech and slow of tongue."
So the LORD said to him, "Who has made man's mouth? Or who makes the mute, the deaf, the seeing, or the blind? Have not I the LORD? Now therefore go, and I will be with your mouth and teach you what you shall say." Exodus 4:10-12
Have you ever believed that God had called you to do something, but feared that you were just not qualified for that roll?
Perhaps God has called you to teach Sunday School, but you have no experience as a teacher, and feel that you don't really know how to handle children.
Maybe God has prompted you to lead a Bible Study or a home fellowship, but you feel you are just not designed to be a leader.
It could be that God has asked you share your faith with a friend, neighbor, or even a total stranger, and you don't think you can find the right words, or that you know the Bible well enough to explain it to someone else.
You could be a parent who knows that God has called you to homeschool your child, yet you question whether you are smart enough, have enough patience, or will be able to get by financially while at the same time committing that much time and energy into your kids.
Or possibly, God has even called you to formal ministry, asking you to become a missionary in a foreign country or a pastor, and you question your ability to handle such a roll, don't know if you are academically inclined for the study such a roll calls for, or feel you have some other roadblock to that ministry.
That is how Moses felt when God spoke to him from the burning bush and told him that he was chosen to deliver the children of Israel from bondage. First he presented God with many questions about how it would work it out, first of all saying, "Who am I that I should go to Pharaoh, and that I should bring the children of Israel out of Egypt?" He was in essence asking God, "Are you sure you've got the right man? I'm no one important." In one sense this attitude was right, he was not looking to himself to try to accomplish this deliverance, perhaps because he had tried that before and it had failed, he knew that he alone could not deliver anyone. (See Exodus 2:11-13 to learn what happened when Moses tried to deliver in his own strength.) However, although part of his attitude was right here, after God assured him that He would be with Him, Moses continued to question. He asked what to do if the children of Israel did not believe that God had sent him and what if the Pharaoh didn't believe Him, all of these questions God answered patiently.
Then Moses pointed to his own inadequacy as a speaker, saying he was slow of speech, as if God would not already have known every strength and every weakness within the man He created. So God once again patiently answers Moses, reminding him that it is He, God, who created every person. It is He who made each one with their inborn strengths and weaknesses, even disabilities. He was aware of every weakness, and yet had chosen Moses, and promised to be with him and with his mouth to teach him what to say.
Who knows, if Moses had stopped questioning God at this point, and simply obeyed, perhaps God would have healed him of his speech impediment, we will never know, because Moses continued on trying to get out of God's calling. Asking the Lord, "Oh my Lord, please send by the hand of whomever else You may send." (Exodus 4:13) Moses was saying, "God, I know you are saying that you will be with me, and that you will give me the words, I know that you are promising to bless this endeavor, but still, I'd rather not do it. Please find someone else, and leave me here to tend my sheep." God became angry at this point, but still did not revoke His call on Moses, rather He sent Moses a helper, a partner, to speak for him.
So back to you, has God called you to do something? If He has has, know that you do NOT need to be "qualified". God has selected you for the task knowing full well that you are not qualified He knows every weakness, every flaw, every disability in your physical, mental, and spiritual makeup. He is aware of you impatience, or lack of education, or inability to concentrate. He knows your fear of public speaking and you inexperience at the task at hand. He even knows all your past sin, the things you've done that you think make you not good enough to serve Him, not only that, He even knows your future sin. Yet, He is calling you anyway.
It is He who made you. He is the one who gave you whatever abilities you do have. Moreover, He is more than capable of putting within you the abilities that you don't yet have. If He has called you to something, He will equip you. He will give you strength, the wisdom, and the skill you need to accomplish what He asks you to do. He will use you in spite of your weakness, so that you will know that it is not you who is really doing the work, but that it is He working through you.
What you must do is obey. It is fine to question God enough for clarification, to ask Him what the next step is, but once He tells you that next step, you must be willing to take it.
As I've said, who knows if God planned to heal Moses' speech impediment had he obeyed right away? Moses asked God legitimate questions, and was answered and reassured, He had clear leading, having heard the voice of YHWH Himself, yet He asked God to send someone else. Perhaps in doing so he missed out on a wonderful blessing of miraculous healing from the hand of God. God is good, and still blessed Moses and his ministry immensely, still used Moses in a mighty way, but it is possible that Moses missed on personal blessing through his reluctance to trust and serve the Lord.
Don't make the same mistake as Moses. If you have God's clear leading and clear calling, go ahead and ask God enough questions so that you know what action He wants you to take next, but once you know that, go ahead and act on what He has told you, take that first step in faith, trusting God to take care of whatever difficulties arise.