By grace, the Spirit uses the sword, which is the Word of God, to "cut" us, precisely, in all the right places and with perfect timing in our lives. And we are grateful for the healing it brings. Heb 4:12, Eph 6:17
We need to understand when/how the apostles' natural abilities were insufficient for the commission they were eventually given. It wasn't enough that Jesus simply called 12 "unexceptional" men. He made a point of training them up before sending them out.