Why did God tell the great missionary Paul of Tarsus, "My grace is sufficient for you. My power is perfected in weak people"? Because the Lord has always used weak people who aspired to be used by an all-sufficient God!
The history of missions is all about weak, barely competent people who believed the One who sent them could accomplish His purposes even through the likes of them! There are only two kinds of people in the world: the weak ones who make themselves available to God and the weak ones who don't.