What does 2 Corinthians 12:15 mean?

This is a beautiful statement about what Paul saw as his purpose in life. He planted the church in Corinth and led many of them to faith in Christ. As a result, he thought of himself as a "spiritual father" to them. He wrote that he would not take money from them for his personal needs (2 Corinthians 12:14), because parents ought to provide for their small children, not the other way around.

Paul would gladly "spend and be spent for [their] souls." Paul saw his life as a resource belonging to God, available to be used up or distributed in order to save and nourish the souls of others. It was more than a mission, though. Paul gladly did so because he loved the Corinthians. He had genuine affection for them.

He acknowledges this is a sticking point between them. Perhaps the false apostles accused Paul of not being a legitimate apostle because he refused payment from the people he served, as they surely did. Paul asks the Corinthians if they love him less because he expresses his love by refusing to take money. He may also be wondering if their failure to stick up for him to the false apostles meant that they loved him less (2 Corinthians 12:11).