The phrase “acid test” referred originally to the process of determining whether or not a metal is gold. It has become a metaphor for determining the quality or nature of a thing. If an interpreter of Romans does not see its threefold structure and/or does not understand Romans 2:13 to be an expression of the law (as distinct from the gospel) or should she reject the law/gospel distinction in principle, then that interpreter is not a reliable guide to the meaning of the epistle to the Romans.
As Luther said, “Therefore whoever knows well how to distinguish the Gospel from the Law should give thanks to God and know that he is a real theologian.”
Whoever, however, does not know how to distinguish law from gospel, is not a theologian and not to be trusted with God’s Word.
Scripture says: “For it is not the hearers of the law who are righteous before God, but the doers of the law who will be justified” (Rom 2:13; ESV). Remarkably, implausibly even (if the Reformation reading of Romans is to be believed), some have proposed that here Paul is making a promise to the Christian, who is united to Christ, about the outcome of his “Spirit-wrought sanctity”. They take this as a promise that the Christian, by grace and co-operation with grace, will be those “doers of the law” who will stand before God justified, at least in part, because of or through their doing.
There could hardly be a more wrong-headed interpretation of Romans 2:13, but that a significant number of people have found such a reading plausible says a great deal about the state of the Reformed understanding of Romans in recent decades. Why is this interpretation incorrect?
First, it ignores the entire structure of the epistle. Romans is in three parts:
Paul’s brief in the first section of Romans is to prosecute Jew and Gentile alike for our original transgression in Adam and our own actual sins and sinfulness. He is preaching the law in its first use to convict sinners so that we might know, as we say in Heidelberg 2, “the greatness of our sin and misery”.
In the second major section of Romans, Paul is preaching the gospel, that we might know (again in the words of Heidelberg 2), how we are “redeemed from all” our “sins and misery”.
The third section of Romans is devoted to the Christian lived by grace alone, through faith alone, in union with Christ and in communion with the visible church, in God’s world.
The three parts of the Heidelberg Catechism—guilt, grace, and gratitude (or sin, salvation, and service)—were patterned after the book of Romans. This is basic, essential, Reformation Christianity. It recognises that there are two different kinds of words in Scripture, the law and the gospel and that Paul speaks those two words in Romans—indeed, he structures the whole book with them.
Second, such a reading, that Paul is making a promise to Christians that they will finally be justified or saved because or through their Spirit-wrought sanctity, ignores the immediate context of Romans 2.
In Romans 1:18–32 Paul has been indicting humanity for sin and illustrating the wickedness, blindness and foolishness of human depravity. In Romans 2:1 he turns to the self-righteous and issues a devastating condemnation: “Therefore you have no excuse, O man, every one of you who judges. For in passing judgment on another you condemn yourself, because you, the judge, practice the very same things” (ESV). God, Paul says, has been patient, forbearing, but we have been impenitent and disobedient.
Then, in vv. 6–8 he foreshadows what he will announce in 2:13: “[God] will render to each one according to his works: to those who by patience in well-doing seek for glory and honor and immortality, he will give eternal life; but for those who are self-seeking and do not obey the truth, but obey unrighteousness, there will be wrath and fury” (ESV). He is saying, in effect, “Alright you self-righteous, let us see how you are faring. The test is set in terms of “works”. He is talking about works righteousness. Verse 11 is important: “For God shows no partiality” (ESV). This is the language of judgment. This a courtroom scene.
Then, to drive the nail into the coffin, in this subsection, he turns to the law: “For all who have sinned without the law will also perish without the law, and all who have sinned under the law will be judged by the law” (Rom 2:12; ESV). This is not about grace but law.
Remember Romans 11:6, “But if it is by grace, it is no longer on the basis of works; otherwise grace would no longer be grace.” As a principle, law is one thing and grace is another. This is why it is unhelpful, so confusing, to speak about “the grace of the law.”
Yes, I understand that antinomians abuse this distinction, but it will help no one to overreact to antinomianism by obliterating an essential biblical and Reformation distinction. Relative to our standing before God, grace is underserved favour and law represents another principle: do this and live.