Bob Deffinbaugh wrote an article on Acts 18:1-7 at Bible.org:
It took a while to realize this, but it is noteworthy that Paul’s first significant success evangelizing among the Gentiles came at this point in time, a time when Paul was at his lowest. He was fearful, both of his safety, and of the results of his ministry if he were to stay on. This is exactly what Paul says in his epistles to the Corinthians. The praise and glory must therefore go to God, and not to men. The pronouncement of Gallio, which was of such importance to the propagation of the gospel, was not the result of Paul’s persuasive speech, for he never got so much as a single word out of his mouth. And the evangelization of the Gentiles was not the result of Paul’s abilities, for he came to them in weakness, fear, and much…
