Apostle Paul was dealing with an ongoing problem in the Corinthian church. He could have refused to communicate until they cleared up their challenges, but he loved them and reached out to them with the love of Jesus Christ.
Love, sometimes means that believers must confront those we care about. Both authority and personal concern are needed in dealing with people who are ruining their lives with sin. But there are several wrong approaches in confronting others, and these can further break relationships rather than heal them.
We can be legalistic and criticise individuals with the laws they should be obeying. Alternatively we can turn away from them because we do not want to face the situation. Believers can isolate them, but do harm by gossiping about their problems and turning others against them as well.
Or like Paul, we can seek to build relationships by taking a better approach-sharing, communicating and caring. This is a difficult approach that can drain us emotionally, but it is best for the other person.
Paul had constantly struggled with those who mislead God’s people and young believers. False teachers were a constant threat to the early church, so he had to spend much time warning and correcting. Paul was reluctant to list his credentials as an Apostle, but boldly gives a strong statement verifying his authority, while pointing out the deception of the false apostles.