And my speech, and my preaching
As he determined, so he acted. As the subject matter of his ministry was not any of the liberal arts and sciences, or the philosophy and dry morality of the Gentiles, but salvation by a crucified Christ; so his style, his diction, his language used in preaching,
was not with enticing words of man's wisdom;
with technical words, words of art, contrived by human wisdom to captivate the affections; and with bare probable arguments only, a show of reason to persuade the mind to an assent, when nothing solid and substantial is advanced, only a run of words artfully put together, without any strength of argument in them; a method used by the false teachers, and which the apostle here strikes at, and tacitly condemns:
but in demonstration of the Spirit, and of power;
partly by making use of solid proofs out of the writings of the Old Testament, indited by the Spirit of God, and which amounted to a demonstration of the truths he delivered; and partly by signs, and wonders, and miracles, and gifts of the Holy Ghost, those extraordinary instances of divine power, which greatly confirmed the doctrines he preached: and besides all these, the Spirit of God wonderfully assisted him in his work, both as to words and matter; directing him, what to say, and in what form, in words, not which human wisdom taught, but which the Holy Ghost taught; and accompanying his ministry with his power, to the conversion, comfort, edification, and salvation of many.