William Burkitt on Acts 14:3

Note here, 1. The manner of the apostles' preaching at Iconium: They spake boldly: that is, openly in the synagogues: and there with great freedom and plainness of speech asserted truth, condemned error, reproved sin, and denounced judgments against impenitent sinners; and this with a wise, but convincing boldness; with a meek, but zealous boldness; knowing, that if they had not now been bold for Christ, they could not at the great day be bold before him. That minister that is afraid to speak and plead for Christ now, will certainly be ashamed to look him in the face then. A serious thought of this, when we are going to preach, will make us shut all base fear out of the pulpit.

Note, 2. The time of their preaching at Iconium: it was not a single sermon or two, in transitu, but long time they abode, speaking boldly in the Lord. A constant course of preaching is needful to root that word which one or two sermons oft leaveth loose; the end of the ministry is to build up, as well as to bring in, and this is done by our constancy in preaching, and exemplariness in holy living.

Note, 3. How God honoured his word in the mouth of his ministers, confirming their doctrine by miracles: He gave testimony by the word of his grace, and granted signs and wonders to be done by their hands. The miracles, which the apostles wrought, were the convincing cause of the credibility of the apostles' testimony.