The Text (ESV)

Paul returns to the theme of Corinthians 1:17: he does not depend on human wisdom or eloquence when preaching the gospel. If a person could be saved through a persuasive argument rather than only through God's working, then that person's faith depends on the quality of the argument and he could be convinced otherwise. This is not to say that Paul did not use logic and reasoning when explaining the gospel. He clearly did as can be seen from Acts 18:4 or his time in Athens (Acts 17). The difference between Paul and the sophists was that his message depended on God's power. Now some use these verses to justify not preparing before preaching so that the Holy Spirit will be able to speak through them. I think that there is a significent difference between depending on fine sounding arguments and spending time in study and preparation. Paul is pointing out problems with the former. I think that he certainly did the latter.

I have thought much about what Paul means by “demonstration of the Spirit” in verse 4: “my speech and my message were not in plausible words of wisdom, but in demonstration of the Spirit and of power.” Does he mean miracles, speaking in tongues, healings? I prefer John Calvin's interpretation: “With this he [Paul] contrasts the demonstration of the Spirit and of power, which most interpreters consider as restricted to miracles; but I take it in a more general sense, as meaning the hand of God powerfully exercised in every way through the instrumentality of the Apostle.”