Paul knew that sometimes we need to be pushed or shoved into doing what we should be already doing.

The Corinthians has promised to send money to the poor saints in Jerusalem, but that was a year ago and still no money. Paul finds a clever way to encourage the Corinthians to follow through with their promise. He also answeres all their questions and concerns before they even get to ask them or use them against him. Now Paul basically doubles down and calls their bluff.
We need not be like the Corinthians and we should be a shining example of chairity towards others. Welcome to the Grace Life unleashed.