When Jesus performed a miracle in Peter's fishing boat as a prelude to calling Peter, James, and John to be his disciples, Peter fell at Jesus' feet and said, "Go away from me, Lord—I am a sinful man!" (Luke 5:8) By declaring himself unworthy, Peter was following in the footsteps of some notable prophets. Immersed in a vision of God's glory, Isaiah declared, "Woe to me! I am ruined! For I am a man of unclean lips, and I live among a people of unclean lips, and my eyes have seen the King, the LORD Almighty." (Isaiah 6:5) When God told Jeremiah he was destined to be a prophet, Jeremiah protested, "Ah, Sovereign LORD, I do not know how to speak; I am only a child." (Jeremiah 1:6) Moses was famous for trying to argue his way out of his calling at the burning bush. Moses argued that he was a nobody and that no one would believe him. He even brought up a speech impediment. But God showed Moses miracles to prove that nothing was impossible for Him. (Exodus 3:1–4:17)
It seems odd from a human standpoint that God would choose all these unqualified people to do His work. God chose David, least among Jesse's sons, to be Israel's most famous king. He gave Joseph the power to interpret dreams when he was nothing more than a betrayed and imprisoned slave. The list goes on and on. And yet all of the unqualified people that God selected were able to do the tasks He set before them. God does not need to choose well-qualified candidates because He makes His servants qualified Himself after He has chosen them. If we feel smugly capable, we deceive ourselves. On our own we can do nothing, and all of our talents and skills are simply gifts from God. When we realize that we are seriously under-prepared and unworthy to do the righteous things God asks of us, then we are ready to receive the divine assistance that can make our success possible.
Consider Paul. When his name was still Saul, he already was an extremely well-educated Biblical scholar and a very intelligent man. Even as Saul prided himself on these qualifications to serve God, he persecuted God's servants. Only after Saul had been confronted by Jesus himself and was left terribly ashamed of his mistakes was he ready to truly serve God. Paul knew that his history of enemity with God's faithful servants should have disqualified him from joining their ranks, but God made it possible. God then went on to use Paul, this former tyrant, to spread the Gospel to thousands of people.
I myself am woefully unqualified to be a child of God. My heart harbors all kinds of sin—jealousy, deceit, spitefulness, anger, and arrogance, to name only a few. I mess up even when I know better, and I often find myself a slave to my emotions. I don't even feel qualified to be God's servant. I don't know how to properly use my talents. I don't know how to get other people to listen to the good ideas I do have, and I feel that I fall short even in my strong suits. None of that really matters, though. I am not God's beloved daughter because I deserve to be—I am because God makes it so. Likewise, God will make it possible for me to accomplish the tasks He sets for me, no matter how unlikely my success may seem by human standards. After all, if God could transform all these unqualified people into Biblical heroes, there are no limits to what miracles He can work in my life.