But I certify you, brethren
Though the Galatians had gone such lengths with their false teachers, yet the apostle still calls them "brethren"; as hoping well of them, that they were born of God, did belong to his family, and were heirs of the grace of life; and this he the rather makes use of, to show his affection to them, and to engage their attention to the assurance he gives, of the divine original and authority of the Gospel preached by him; which though they formerly knew and believed, yet through the insinuations of the false apostles, were drawn into some doubts about it: wherefore he declares in the most solemn and affectionate manner,
that the Gospel which was preached of me, is not after man.
Their guides that were leading them wrong, did not presume to say, that the Gospel was after man, for they themselves pretended to preach the Gospel; but that the Gospel preached by the apostle had no other authority than human, or than his own to support it: wherefore he denies that it was "after man"; after the wisdom of man, an human invention and contrivance, a device and fiction of man's brain; nor was it after the mind of man, or agreeably to his carnal reason, it was disapproved of by him, and beyond his capacity to reach it; nor was it of his revealing, a discovery of his; flesh and blood, human nature, could never have revealed it; nor is it in the power of one man to make another a minister of the Gospel, or to give him or himself success in the ministration of it, but the whole is of God.