Note 9 at 1 Cor. 4:20: There were some in Corinth who had challenged Paul's apostolic authority (1 Cor. 1:12; 3:4; 4:3). In Paul's absence they were bold to speak against him. But Paul is promising to return to Corinth and settle all disputes, not with words, but through the power of the Holy Spirit.

This is comparable to what Paul said in chapter two (see note 1-2 at 1 Cor. 2:1-2, p. 866). Paul used persuasive words, but his faith was in the power of the Holy Spirit to convict men's hearts. One of the ways the Holy Spirit demonstrated His power through Paul was by miraculous healings and deliverances (see note 4 at 1 Cor. 2:4, p. 866). Paul used the miraculous manifestations of the Holy Spirit through him as a verification of his apostolic calling (2 Cor. 12:12).

Therefore, Paul is proposing a test similar to what Elijah did with the prophets of Baal in 1 Kings 18. Those who oppose Paul will have to demonstrate the power of the Holy Spirit in their lives or shut up. Talk is cheap but actions are powerful.

"The Epistles of Paul" translated by W.J. Conybeare says it this way, "For mighty deeds, not empty words, are tokens of God's kingdom."

If we today would discern an individual's authority by his power instead of just his words, very few cults would exist.