“The background of δικαιοσύνη θεοῦ is in Israel’s sacred traditions which present God’s ‘righteousness’ as somewhat equivalent to God’s ‘salvation.’ In some cases righteousness is predicated of God’s mighty acts (Jdgs. 5:11; 1 Sam. 12:7). . . Righteousness appears elsewhere not as God’s action, but as the basis and rationale for his saving actions. As such it can connote God’s faithfulness to his covenantal promise to Israel. An important qualification to be noted is that although God’s righteousness occurs in proximity to salvation or the basis of him providing salvation, there are other contexts where God’s righteousness takes on a punitive function. God’s righteousness is expressed in enacting salvation for Israel by executing judgment against pagan nations that oppress Israel. Elsewhere, Israel can be indicted for their wickedness by God’s righteousness. To speak of the δικαιοσύνη θεοῦ is to say something about the righteousness of God’s character and how he demonstrates his character as the judge of all the earth and in his faithfulness towards Israel. The righteousness of God then is the character of God embodied and enacted in his saving actions which means vindication (for Israel and the righteous) and condemnation (for the pagan world and the wicked).
I submit that the foregoing context provides the background for Paul’s explication of the δικαιοσύνη θεοῦ in his letters. God’s righteousness denotes the saving action of God now revealed and now manifested in the gospel of Jesus Christ. A subjective genitive seems more appropriate given that the δικαιοσύνη θεοῦ stands in proximity and parallel to the ‘power of God’ (Rom. 1:16), the ‘wrath of God’ (Rom. 1:18; 3:5), the ‘faithfulness of God’ (Rom. 3:5), and the ‘truthfulness of God’ (Rom. 3:7; 15:8). The righteousness of God is revealed in the gospel as the outworking of God’s saving power. The righteousness of God is not the result of the gospel, but what empowers it and ensures its efficacy. Hence the righteousness of God should not be equated with justification by faith or the imputation of righteousness. The phrase δικαιοσύνη θεοῦ is not a synonym for δικαιόω [‘to justify’]. There would be some grounds for making the two equivalent if Romans ended at chapter four and Galatians at chapter three–but that’s not what we find. . .
Appeals to Rom. 10:3 where the ‘righteousness of God’ stands in contrast with ‘their own’ righteousness is in fact counter-productive to viewing δικαιοσύνη θεοῦ as strictly righteousness bestowed as a gift. The problem with Paul’s fellow Jews is not that they did not ‘receive’ God’s righteousness but that they did not ‘submit’ to it. Can one submit to a gift? Though Paul does speak of righteousness as a gift and a new status (Rom. 3:22-24, 5:15-17 and Phil. 3:9), that is hardly the sum meaning of the δικαιοσύνη θεοῦ. Thus the righteousness of God, at least in Rom. 1:17, introduces the entire package of salvation including justification, redemption, propitiatory sacrifice, forgiveness of sins, membership in the new covenant community, reconciliation, the gift of the Holy Spirit, power for a new obedience, union with Christ, freedom from sin, and eschatological vindication. God’s righteousness is an all-encompassing action that includes both redemption and renewal. I concur with the thought of Dunn: ‘The righteousness of God is nowhere conceived as a single, once-for-all action of God, but as his accepting, sustaining, and finally vindicating grace.’ God’s righteousness is all that God does in salvation on our behalf. God’s righteousness then is a subjective genitive describing his power in effecting salvation. More precisely God executes or enacts his righteousness in the death and resurrection of Jesus Christ.
Whereas the ‘righteousness of God’ comprises a conceptual host to all of Paul’s salvific imagery, I do not think that the same can be said of δικαιόω (‘to justify’) which is strictly forensic. Justification is the contingent legal metaphor that Paul uses to articulate his central point, namely, the end of God’s contention against sinful humanity and their acceptance into God’s family in a new redemptive relationship. The evidence that δικαιόω is forensic is quite overwhelming.”
Bird, Michael F. The Saving Righteousness of God: Studies on Paul, Justification, and the New Perspective, pp. 14-17).