So you also, when you have done everything you were told to do, should say, "We are unworthy servants; we have only done our duty." —Luke 17:10
Although we don't deserve it, there is God's promise to us in our showing gratitude. Gratitude shown, even keeping our vows, contains great promise! God does not have to promise us anything for our showing thankfulness. We ought to be thankful to Him for His goodness. Period. End of story. But I can tell you that He delights in rewarding those who show that they are grateful to Him. God does not have to promise us blessing if we tithe, but He does. (See Malachi 3:10.) God does not have to promise us blessing for forgiveness, for not judging, and for giving to others, but He does. (See Luke 6:37-38.)
In other words, our obedience to show gratitude is required of us. "So you also, when you have done everything you were told to do, should say, 'We are unworthy servants; we have only done our duty'" (Luke 17:10). Obedience is duty. But God is so good, so kind, so merciful! We cannot out-praise the Lord, out-give the Lord, or out-thank the Lord!
He has chosen to show His pleasure when we get it right and do it right. For those strong enough in themselves that they need no further affirmation from God or recompense, I say, "Good for you." But I, for one, am not that strong. I need affirmation and all the encouragement I can get. I sometimes come to tears when I read those words of David: "For he knows how we are formed, he remembers that we are dust" (Ps. 103:14). I am so weak that I need all the motivation I can get to press on with any kind of obedience, and that includes the obedience of gratitude.
Excerpted from Just Say Thanks! (Charisma House, 2005).