It was that, being puffed up with ambition, that they might secure for themselves the admiration of the people, they recommended themselves to them by a show of words and mask of human wisdom.
From this main evil two others necessarily followed—that by these disguises (so to speak) the simplicity of the gospel was disfigured, and Christ was, as it were, clothed in a new and foreign garb, so that the pure and unadulterated knowledge of him was not to be found. Farther, as men’s minds were turned aside to neatness and elegance of expression, to ingenious speculations, and to an empty show of superior sublimity of doctrine, the efficacy of the Spirit vanished, and nothing remained but the dead letter.
The majesty of God, as it shines forth in the gospel, was not to be seen, but mere disguise and useless show. Paul, accordingly, with the view of exposing these corruptions of the gospel, makes a transition here to the manner of his preaching. This he declares to be right and proper, while at the same time it was diametrically opposed to the ambitious ostentation of those men. It is as though he had said—“I am well aware how much your fastidious teachers delight themselves in their high-sounding phrases. As for myself, I do not simply confess that my preaching has been conducted in a rude, coarse, and unpolished style, but I even glory in it.
For it was right that it should be so, and this was the method that was divinely prescribed to me.” By the wisdom of words, he does not mean λογοδαιδαλία, which is mere empty talk, but true eloquence, which consists in skillful contrivance of subjects, ingenious arrangement, and elegance of expression. He declares that he had nothing of this: nay more, that it was neither suitable to his preaching nor advantageous.
[John Calvin, Commentaries on the Epistles of Paul the Apostle to the Corinthians Vol. 1, ed. J. Pringle (Grand Rapids: Baker, 1974), 73-74.]