It is all for your sake, so that as grace extends to more and more people it may increase thanksgiving, to the glory of God. (2 Corinthians 4:15)
Gratitude flourishes in the sphere of grace. And that is why the play on words in 2 Corinthians 4:15 is significant. Grace is charis and gratitude is eucharistian because gratitude is a response to grace. Gratitude is the feeling of happiness you feel toward somebody who has shown you some undeserved kindness, that is, who has been gracious to you.
This close relationship between grace and gratitude can be illustrated even in situations where it looks like we contradict it. For example, kind people often say, “Thank you,” even where it is unnecessary. Even in places where goods are being fairly traded, value for value, we often say, “Thank you.” Why? One reason is that there are often little things people do beyond the demands of the bare transactions which benefit us — like a smile or an encouraging word or a gentle and caring demeanor. These we sense as unpaid for grace and so we feel gratitude in our heart for them.
But there is another reason we often say thanks when people are merely doing for us what we've paid for. Since gratitude is universally known as a feeling that comes in response to grace, expressions of gratitude have come to be used as expressions of humility and encouragement. When we say, “Thank you,” to someone, we humble ourselves as a person who has needs, and we exalt them as one who can meet those needs.
For example, in a restaurant why do I say, “Thank you,” to the waitress for bringing my meal? I will pay for it, and I will tip her. She is doing nothing beyond her duty and may not even be cheerful. The reason is that “thank you” is a gesture of humility that says to her: I am not eager to exalt myself as one to whom you owe service. I do not wish to presume upon your work as my due. I am happy to put myself in the position of one who receives grace. I am happy to honor you as one who can meet my need.
The reason a simple, unnecessary “thank you” can say all this is because of its close association with grace. Since the feeling of gratitude usually rises in our hearts when someone does us an undeserved or uncalled-for favor, the expression of thanks will at any time communicate humility (I am a mere beneficiary of grace) and encouragement (you are my needed and helpful benefactor).
Now with this insight into the meaning of gratitude and its relation to grace we can understand our text more fully. Paul says that his ministry “is all for your sake, so that as grace extends to more and more people it may increase gratitude to the glory of God.” The reason the spreading of grace increases gratitude is because gratitude is the happy feeling directed toward a person who does us some undeserved favor. The person our gratitude is directed to in verse 15 is Jesus Christ and God the Father through him. In verse 5 Paul said, “What we preach is not ourselves but Jesus Christ as Lord.” Therefore, the grace that spreads as Paul pursues his ministry is the grace given by Jesus. Chapter 8, verse 9, defines this for us pretty clearly: “For you know the grace of the Lord Jesus Christ, that though he was rich, yet for your sake he became poor, so that by his poverty you might become rich.”
Grace begins when one person is full and another is empty. One person is a have and the other a have-not. One is rich; the other is poor. Then grace comes into action as the emptiness of one is filled up by the fullness of the other. What we do not have is supplied by what he has. Our poverty is replaced by his wealth. And all that not because we deserve it, but because Jesus is gracious. His riches are free. Therefore, gratitude wells up in the hearts of those who “receive the abundance of grace and the free gift of righteousness” (Romans 5:17).
This gratitude to Christ which marks all true believers (Romans 1:21) is more than saying, “Thank you,” or trying to return some service; it is more than being glad you are free from condemnation; it is being glad toward Jesus for the riches of salvation and the way he made it ours. When the grace of Jesus penetrates the human heart, it rebounds back to God as gratitude. Christian gratitude is grace reflected back to God in the happiness we feel toward Jesus.