Luther translated “dikaiosuvnh ga˝r qeou:” as a genitive of source[1] causing him to interpret Paul’s phrase as the “righteousness from God.”[2] From this translation Luther was convinced that “the righteousness of God” in verse 17 had nothing to do with punishing sinners in his righteousness, but it was God granting sinners a righteous status. Therefore, Luther concluded, “the righteousness of God” is “the righteousness from God.” The believer receives a righteousness that is not of himself, but of a holy and perfect God.
One important concept crucial to Luther’s theology of Romans 1:17 is that “the righteousness of God” is “purely forensic,” a judicial standing/status. Luther wrote, “the righteousness of God is not to be understood as the righteousness by which one becomes righteous of himself, but that by which we are made righteous by Him; and that is done through faith in the Gospel.” To put simply, Luther did not advocate that this righteousness internally renewed or morally transformed the person.[3] Nygren puts it, “the meaning is not that, having had a divine gift infused into him, he now has it as a property or inner quality.”[4]
[1] Daniel Wallace defines genitive of source a “simple genitive being replaced by a prepositional phrase (in this instance, ejk + gen.) to indicate source.” Therefore instead of using the genitive keyword “of”, it is replaced with the phrase “out of,” “derived from,” “dependent on,” or “sourced in.” Daniel B. Wallace, Greek Grammar Beyond the Basics: An Exegetical Syntax of the New Testament. (Grand Rapids, MI: Zondervan, 1996). 109.
[2] Douglas J. Moo, The Epistle to the Romans, The New International Commentary on the New Testament. (Grand Rapids, MI: Eerdmans, 1996). 71. Also Osborne page 42.
[3] “Luther viewed this righteousness as purely forensic – a matter of judicial standing, or status, and not of internal renewal or moral transformation.” Douglas J. Moo, The Epistle to the Romans, The New International Commentary on the New Testament. (Grand Rapids, MI: Eerdmans, 1996). 71. Along the lines of Moo, Grant R. Osborne defines it is a less grammatical way, “Of God can refer to source or orgin, giving the phrase a forensic or legal aspect referring to God’s judicial decision to “declare us righteous” on the basis of Christ’s sacrifice on the cross for our sins. In this way God imparts a new status to believers, namely, that they are now the children of God. This was Luther’s view, and it has been highly influential in Protestantism.” Grant R. Osborne, Romans, The IVP New Testament Commentary 6. (Downers Grove, IL: Intervarsity Press, 2003). 42.
[4] Anders Nygren, Commentary on Romans. (Philadelphia: Fortress, 1949). 75.