What does 2 Corinthians 6:13 mean?

Paul has written that his heart, and the heart of his fellow workers for Christ, is wide open to the Corinthians. He means they have as much love and affection for the Christians in Corinth as they have ever had. This is regardless of any conflict between them or how freely he has written to them to clear up any disagreements.

The same is not true of the Corinthians, Paul has said. They have restricted their hearts toward him and his ministry partners. Either in resentment for correcting their spiritual errors, or because of the false teaching of some among them, at least some Corinthians had lost at least some of their love for Paul.

Paul now urges them to widen, or fully open, their hearts to him, as well. Paul says he speaks as to children, likely meaning he considers the Corinthians his spiritual children (1 Corinthians 4:14–15; 2 Corinthians 12:14–15). He wants to have a close, honest, and loving relationship with them as a good father does with his kids.