GIVE ALL THE GLORY TO GOD
John 17:18 "As thou hast sent me into the world, even so have I also sent them into the world."
We are not from the world. Through the new birth, we come from God and should constantly remind ourselves of this. It is not good to be too "at home" in the world. We are in the world but are not of the world. Great men and women of God have always had this attitude.
The primary reason that God chooses to use those who are nothing by the world's standards, is so no one else can take credit for the great things that are accomplished.
If the Lord used those who had it "all together" in the natural, then they would share the glory that rightfully belongs to God alone. But when the Lord works miraculously through someone who obviously has no talent or ability, then everyone says, "This must be God."
Not only does this keep others from misdirecting the glory that belongs to God, but it keeps the person who God uses from swelling up with pride. One of Satan's greatest weapons against someone who is being used by God is to tempt them to think that the Lord is using them because they possess some superior virtue.
God uses "nobodies." If we think we've become "somebody" (in our flesh), then we will cease being used. He will not share His glory with anyone else (Isa. 42:8).