In the early chapters of Romans, Paul the prosecutor has summarily indicted all of mankind; Jew and Gentile, as guilty before God. Part of his case has been a dismantling of the Mosaic Law as having any part in providing humanity with a right standing before God. The law cannot do this for at least two reasons. First, no one keeps the law. “None is righteous, no, not one” (3:10) Second, the law reveals sin, it does not overcome it. “Through the law comes knowledge of sin.” (3:20) It is not all bad news, however. “But now the righteousness of God has been manifested apart from the law.” (3:21)
Given this setting aside of the law of God, some of Paul’s readers, particularly Jewish ones, were apt to ask whether Paul has set aside the patriarchs themselves, and the history of God’s dealing with them. Was all of that for naught?
Paul anticipates the argument with his question at the end of the chapter. “Do we then overthrow the law by this faith?” But he quickly answers, “By no means! On the contrary, we uphold the law.” (3:31)
From this verse, some have taken the apostle to mean that Christian living by faith is moral living, that is, that it conforms with and indeed upholds God’s law. Christian living is not in conflict with the law of God, but this is not at all what Paul here claims. Law can be used in more than one sense, and to restrict it to the moral law, or the Ten Commandments or any statute of the Old Covenant is to overly constrain the meaning. The law can mean the Pentateuch. “…everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled.” (Luke 24:44)
It can also mean the commandments that comprise the entire body of statutes given to Israel. “…the parents brought in the child Jesus, to do for him according to the custom of the Law.” (Luke 2:27) Finally, it may be restricted to the Ten Commandments. Paul affirms, “For I would not have known what it is to covet if the law had not said, ‘You shall not covet.” Clearly, the apostle is not talking about the entire Pentateuch, but only the last of the Ten Commandments, which he refers to as “the law.”
In what sense, then, does Paul use the word law here at the end of Romans? If he means it as the commandments of God, those statutes given to the nation of Israel, then perhaps it is true that faith “upholds the law.” But Paul does not use the word in this meaning. Rather, it is clear from the following chapter that the apostle means the broadest sense of law possible—the law and the prophets. Paul is making no commentary on holy living by believers here. He is instead showing that the history of God’s dealings with the patriarchs does, in fact, demonstrate justification by faith, the thing he insists on in this epistle. He begins with Abraham.
What then shall we say was gained by Abraham, our forefather according to the flesh? For if Abraham was justified by works, he has something to boast about, but not before God. For what does the Scripture say? “Abraham believed God, and it was counted to him as righteousness. (4:1-3)
Abraham was justified by faith, entirely apart from works, and his circumcision was “a seal of the righteousness that he had by faith while he was still uncircumcised.” (4:11) The law upholds faith because it shows our father Abraham was justified by this very principle. Paul goes on to David.
“David also speaks of the blessing of the one to whom God counts righteousness apart from works:
“Blessed are those whose lawless deeds are forgiven,
and whose sins are covered” (4:6-7)
He, too, attributes righteousness to faith, apart from works. If we look previously in chapter 3:21, we can see a hint of this. In the first half of the verse, law is in lowercase. This denotes the use of the word as synonymous with the commandment and adherence to statutes. Paul has said that God imputes to us his righteousness apart from such law-keeping. But the second half has the word Law in uppercase, and with the additional phrase “and the Prophets.” The editorial decisions of the English Standard Version thus show these different senses of the word law. In short, verses 21 and 31 are in full agreement, showing that the Old Testament contained justification by faith, and is no novelty with Paul. Paul has not undercut the witness of the patriarchs in the law, he has upheld it.
Christian living is not lawless living, but Romans 3:31 is not the place to look for such doctrine. Paul will show in many other places how the Christian fulfills the law, even without striving to keep it. For a fuller discussion, see If One Uses It Lawfully: The Law of Moses and the Christian Life.