Paul reasoned with people. Paul presented them with logical arguments based upon scripture, in order to secure their voluntary consent. In order to secure their voluntary submission and giving up control to Almighty God.
Brethren, the power (and authority) in the ministry is in the exercise of the gift of God. In Ephesians 4, beginning in verse 7—Christ gave men gifts; and, in turn gave them to the church. The power and authority in the ministry is in the exercise, by the minister, of the gift of God in fulfilling their responsibility.
Their power, then, is in the use of persuasive language that is in harmony with the truth of God—which will, in turn, stir the Spirit of God in people and encourage (and motivate) them to follow.
"In humility." There it is. Connect that with Philippians 2. Humility is the way to leadership. Humility is the way to exaltation—God's way.