Note 4 at 2 Cor. 13:4: Paul had just spoken about how some of his accusers had characterized him as being weak and ineffective (v. 3). He refuted that accusation. He now likens his perceived weakness to the way people perceived Christ to be weak when He was crucified. The truth is Christ wasn't weak. He proved that by His resurrection. As the song goes, "He could have called ten thousand angels" that would have delivered him in an instant (Mt. 26:53). Likewise, those who believe Paul to be weak were mistaken.

It is true that Paul had limitations as we all do, but Paul wasn't living by his own power. Paul was no longer living out of the weakness of his flesh but was letting the living, indwelling Christ control his life (Gal. 2:20). As Paul realized his own weakness and turned to Christ, he was truly strong (see note 27 at 2 Cor. 12:10, p. 1043). Likewise, our strength doesn't lie in our "old self," but in our total dependence on Christ in us (Col. 1:27).