Note 12 at 2 Cor. 11:7: Paul is asking if he had sinned by preaching the gospel free of charge to the Corinthians. He humbled himself by making tents to support himself and his companions in ministry (1 Cor. 4:12; 1 Th. 2:9; 2 Th. 3:8). While other religious teachers and philosophers demanded payment for their services, Paul showed unselfish service towards those to whom he ministered.

Paul is pointing out the irony of these accusations against him. How could anyone receive an evil report against someone who had served them so selflessly? His actions should have spoken for themselves. In verse 12 Paul said the reason he had done this was to stop false apostles. How could someone who was charging for his services impugn someone who gave everything he had freely? Yet this is the situation Paul found himself in.