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 is joy toward God for his grace. But by its very nature, gratitude glorifies the giver. It acknowledges its own need and the beneficence of the giver.
Just like I humble myself and exalt the waitress in the restaurant when I say, “Thank you,” to her, so I humble myself and exalt God when I feel gratitude to him. The difference, of course, is that I really am infinitely in debt to God for his grace, and everything he does for me is free and undeserved.
But the point is that gratitude glorifies the giver. It glorifies God. And this is Paul’s final goal in all his labors: for the sake of the church — yes; but, above and beyond that, for the glory of God.
The wonderful thing about the gospel is that the response it requires from us for God’s glory is also the response which we feel to be most natural and joyful, namely, gratitude for grace. God’s glory and our gladness are not in competition.
A life that gives glory to God for his grace and a life of deepest gladness are always the same life. And what makes them one is gratitude.