The essence of sin is misguided gratitude, not ingratitude. As dependent creatures we all, by nature, thank somebody or something (usually ourselves!) for what we experience and achieve. And the ultimate object of our gratitude becomes the object of our worship. In turn, the object of our gratitude becomes the object of our service, since we inevitably serve whatever or whomever we think will meet our needs (see Matthew 6:24). This is why, in Romans 1:25, worship and service are linked together: the object of our worship always becomes the master of our behavior. This is a law of human nature, inasmuch as God made us to worship and live for him. The sin of idolatry, whether in the age-old worship of nature or in the modern worship of ourselves, is consequently the same: worshiping and serving the creature rather than the Creator (see Romans 1:25).

Idolatry, whether ancient or modern, is thus the futile attempt to look for our lives to anyone or anything other than the one true Creator and Provider. Whom do I thank when things go well? To whom do I look when things go badly? What is my source of security? Where do I gain my sense of worth in the world? What am I striving to achieve in life, and why? The answers to questions like these will help determine whether we are honoring God as God or whether we are idolaters—whether that means we are praying to a stone image as in the prophet Isaiah's day, drooling with envy over the car in our neighbor's driveway, or latching onto the latest self-help strategy.