And my speech and my preaching [was] not with enticing words of man's wisdom, (2) but in (d) demonstration of the Spirit and of power:
(2) He turns now to the commendation of his ministry, which he had granted to his adversaries: for his strength and power, which they knew well enough, was so much the more excellent because it had no worldly help behind it.
(d) By "demonstration" he means such a proof as is made by reasons both certain and necessary.