In 1 Thessalonians 5:18, the Apostle Paul challenges Christians to “give thanks in all circumstances” and then reinforces the importance of that command by declaring that “this is the will of God in Christ Jesus for you.” In speaking this way, Paul reminds us how central gratitude is to the Christian life. Being grateful is not optional for God’s people. It is—or ought to be—part of the warp and woof of the life of every believer.

That is why in Romans 1:21, Paul links ingratitude toward God with a failure to “honor him as God.” He knows that when we are ungrateful toward God, we fail to treat Him as God and instead put ourselves in His rightful place. We do this by taking credit for the good things that happen to us in our lives, either by believing that we have brought these positive circumstances about by our own ingenuity, resourcefulness, strength, and hard work or by thinking that we have somehow deserved them because of who we are and what we have done. When we think and act this way, we fail to honor God as God, and we absorb for ourselves the gratitude that God alone is due.

But we also fail to treat God as God by questioning His wisdom and goodness when our circumstances don’t go the way we want them to go. When we grumble and complain about having our wallets stolen, our reputations maligned, or our lives turned upside down by some other kind of hardship, we are saying that we know better than God does. We are saying that something is wrong with His providential care of the world or, worse, that something is wrong with Him—namely, that He must not be all-wise or all-loving or altogether good. Ingratitude in adverse circumstances is therefore just as prideful as the ingratitude we display in the best of circumstances. In both cases, we are refusing to give God the glory that He alone is due or, in the words of Romans 1:21, we are not honoring God as God.

The point in all this is simply to say that when we are ungrateful, we are acting like non-Christians. We are acting as though God did not exist. Ingratitude is not a sin that we should wink at or be unconcerned about. It strikes at the very core of the Christian faith, because it treats God as though He were not God. And what is more, ingratitude cheapens grace. It overlooks the cost of the gift of salvation that we have been given and diminishes the value of that gift by ascribing greater value to something else that God, in His providence, has chosen not to give us. That may be the real and lasting tragedy of ingratitude. It devalues the person and work of Jesus Christ, who really is the Pearl of Great Price (Matt. 13:46) and the Fairest among ten thousand (Song 5:10).

Dr. Guy M. Richard is president and associate professor of systematic theology at Reformed Theological Seminary in Atlanta. He is author of several books, including What Is Faith? and Baptism: Answers to Common Questions.