This quote from a sermon by Tim Keller has stayed in my mind ever since I heard it, and I believe every word:
My dear friends, most churches make the mistake of selecting as leaders the confident, the competent, and the successful. But what you most need in a leader is someone who has been broken by the knowledge of his or her sin, and even greater knowledge of Jesus’ costly grace. The number one leaders in every church ought to be the people who repent the most fully without excuses, because you don’t need any now; the most easily without bitterness; the most publicly and the most joyfully. They know their standing isn’t based on their performance.
That’s the kind of leadership we need.