In 2007, Tim Keller penned an excellent (lesser known) article entitled “Talking about Idolatry in a Postmodern Age“. There has been a considerable amount of material published about idolatry, including articles, books, and sermons from various evangelical leaders. Perhaps none have been more helpful in helping to shed light on functional idolatry than Tim Keller.

In this little article, Keller draws from Martin Luther’s Treatise on Good Works to make an insightful relationship of the law to the gospel. Keller via Luther makes the case that by breaking any of commandments two through nine necessarily includes breaking the first commandment. In other words, the command “have no other gods before me” is violated when idolatry is functionally manifested in violating any of the other commands. Here’s the pertinent excerpt from Keller’s article where he explains this insight:

No one grasped this better than Martin Luther, who ties the Old Testament and New Testament together remarkably in his exposition of the Ten Commandments. Luther saw how the Old Testament law against idols and the New Testament emphasis on justification by faith alone are essentially the same. He said that the Ten Commandments begin with two commandments against idolatry. It is because the fundamental problem in law-breaking is always idolatry. In other words, we never break the other commandments without first breaking the law against idolatry. Luther understood that the first commandment is really all about justification by faith, and to fail to believe in justification by faith is idolatry, which is the root of all that displeases God.

All those who do not at all times trust God and do not in all their works or sufferings, life and death, trust in His favor, grace and good-will, but seek His favor in other things or in themselves, do not keep this [First] Commandment, and practice real idolatry, even if they were to do the works of all the other Commandments, and in addition had all the prayers, obedience, patience, and chastity of all the saints combined. For the chief work is not present, without which all the others are nothing but mere sham, show and pretense, with nothing back of them… If we doubt or do not believe that God is gracious to us and is pleased with us, or if we presumptuously expect to please Him only through and after our works, then it is all pure deception, outwardly honoring God, but inwardly setting up self as a false [savior]…. (Part X. XI) Excerpts from Martin Luther, Treatise Concerning Good Works (1520).

Here Luther says that failure to believe that God accepts us fully in Christ—and to look to something else for our salvation—is a failure to keep the first commandment; namely, having no other gods before him. To try to earn your own salvation through works-righteousness is breaking the first commandment. Then he says that we cannot truly keep any of the other laws unless we keep the first law—against idolatry and works-righteousness. Thus beneath any particular sin is this sin of rejecting Christ-salvation and indulging in self-salvation.

For example, letʼs say a person cheats on his income tax form. Why does he do that? Well, you say, because he is a sinner. Yes, but why does his sin take this form? Lutherʼs answer would be that the man only cheated because he was making money and possessions—and the status or comfort from having more of them—more important than God and his favor. Or letʼs say a person lies to a friend rather than lose face over something she has done. In that case the underlying sin is making human approval or your reputation more important than the righteousness you have in Christ.

The Bible, then, does not consider idolatry to be one sin among many (and a rare sin found only among primitive people). Rather, all our failures to trust God wholly or to live rightly are at root idolatry—something we make more important than God. There is always a reason for a sin. Under our sins are idolatrous desires. (emphasis mine)

When I contemplated the relationship of justification by faith with functional idolatry, it helped me explore the ways I seek to find self-justification through violation of the law of God. As Keller noted, there is a reason why we lie. It is because we find greater comfort in believing falsehood rather than being exposed by the truth. When we are justified by faith in Christ alone, we are freed to be a people who love truth and are willing to live exposed to the truth of God’s Word (Heb. 4:12-13).

There is a reason why we steal. It is because we do not trust in God’s provision for our lives and value the stuff of others (going from I like to I want to I must have at all cost) to the point of making them our own.  When we are justified by faith in Christ alone, we are freed to be a people who no longer steal but work with our own hands to provide for others in need (Eph. 4:28). Where self-salvation led to depriving others of their belongings because of functional idolatry, the salvation Jesus brings leads to generosity for others because you value Jesus more than anything else in this world.

This kind of elaboration can extend throughout God’s law. I think Luther and Keller are right. When we break God’s law, functional idolatry has taken place. No only have we outwardly violated God’s revealed will, but inwardly (the sin beneath the sin) we manifest a life under our rule (instead of God’s) and justification for living for self-salvation and satisfaction. When we are justified by faith alone in Christ alone, we turn from idolatry in repentance and faith in ways that the gospel fuels obedience in every way idolatry fueled our disobedience.

Taking the counsel of Luther, we can discover specific ways to apply the gospel to our lives and grow in repentance and faith. When we cry, “I believe; Lord, help my unbelief!” God’s law shows us the various ways we are prone to functional idolatry and where can turn with fresh repentance and faith to all that God has given us in Christ.