As pastors, we are spiritual leaders whose goal is "moving people on to God's agenda" (Blackaby, Spiritual Leadership). God uses pastors to persuade people to reconcile broken relationships as we follow the Lord together (2 Cor. 5:18). Pastoral leadership is all about influencing others. In this case, Paul wants to persuade them to "make room" (Χωρήσατε) for him in their hearts.
They say that fences make good neighbors. Fences also make good pastors. Since pastoral persuasion is moving people to follow God's will, God places ethical boundaries on our persuasion. These fences ensure that Pastors will submit their persuasive methods to God's sovereign control. We dare not manipulate others for our own ends or else we deny our Lord by our actions.
Paul lays out three fences in this verse to guard against unethical influence. He uses three verbs. Each verb is aorist, active indicative. They are best understood as constative aorists. Paul is saying that their ongoing actions in each case have been completed and should be regarded as a whole (Blass/Debrunner, Grammar, 171). The plural pronoun (we) likely included Timothy, who represented him in a difficult confrontation, and Titus, who carried his harsh letter of rebuke (F.F. Bruce, Paul: Apostle of the Heart Set Free, 273-274). Paul has proven himself in these three ways to be an ethical persuader.
FENCE #1: DO NO HARM.
Paul starts with the bare minimum. At the very least, pastors should do no harm. He says that he "wronged" (ἠδικήσαμεν) no one in Corinth. The verb was commonly used in the Septuagint to refer to sin against God, however, in the New Testament, it has lost much of that stronger meaning. The usage in the New Testament suggests general wrongdoing. When used with an object like a person, it often means to hurt someone (TDNT, 1:157-161). Pastors, at the very least, must not hurt people, hardly a high bar for ethics!
FENCE #2: LEAD NO ONE ASTRAY.
The verb (ἐφθείραμεν) generally means to corrupt or ruin with respect to morals, money or doctrine (Rienecker and Rogers, Linguistic Key, 475). Paul uses the same word a few chapters later (2 Cor. 11:3) to warn the Corinthians that they could be "led astray" (φθαρῇ) by Satan "from the simplicity and purity of devotion to Christ." Paul also writes "Do not be deceived: Bad company corrupts (φθείρουσιν) good morals" (1 Cor. 15:33). He is warning believers not to keep company with those who deny the resurrection of the dead and promote sinful living (NIDNTT, 1:468-469). Pastors must be careful not to lead others astray morally or doctrinally.
FENCE #3: DON'T USE PEOPLE FOR PERSONAL GAIN.
The verb translated "took advantage of" (ἐπλεονεκτήσαμεν) literally means to have more of something. In the Greco-Roman world it meant a hunger for power or to seek political gain. The idea included treating others arrogantly. Paul uses it frequently to mean seeking material possessions by taking advantage of people. Paul even commanded that we avoid anyone who coveted possessions and placed coveteousness (πλεονέκτης) on par with sexual sin (1 Cor. 5:10-11). False prophets exploit people out of greed (πλεονεξία) leading to God's judgment (2 Peter 2:3). Paul warns pastors not to use flattery or greed (πλεονεξίας) because God examines our hearts (1 Thess. 2:4-5). A pastor must not cheat or defraud anyone. We must not abuse our power to get our way (TDNT, 6:266-274).
Effective pastors work within God's fences for healthy persuasion.