Note 11 at 2 Cor. 13:10: Paul is referring to the letter he had just written to the Corinthians. He preferred to write and get things straightened out rather than to be harsh when he saw them in person. Paul used his Apostolic authority to build up and not to tear down.

Note 12 at 2 Cor. 13:10: Paul had referred to the authority that he had in Christ as the apostle of the Corinthians many times in these two letters. But Paul didn't use his authority in an abusive fashion. It was a gift from God to edify believers, not terrify them. Those who use their "authority" in a destructive manner should be suspect as to whether or not this is really God's authority (see note 14 at 2 Cor. 10:8, p. 1030).