. . . the interpretation of δικαιοσύνην θεοῦ in James 1.20 is thorny. The noun δικαιοσύνη alone could refer to (1) a
quality of fairness, (2) correctness based on redemptive action, or (3) a
characteristic of uprightness. . . . a case can be made that δικαιοσύνην θεοῦ
refers to justification be bestowed by God, the second usage of δικαιοσύνη.
This would make θεοῦ a subjective genitive, consistent with δικαιοσύνην θεοῦ
elsewhere in the NT (e.g., Rom. 1.17; 3.5, 21-22; 10.3; 2 Cor. 5.21). McKnight
correctly points out an intimate association between standing before God
and a behavioural moral attitude as a result of redemption. He cites
God’s saving action as described by δικαιοσύνη in LXX Isa. 46.13 (McKnight, Letter
of James, p. 139). It would also preserve the parallel between οργη ανδρος and δικαιοσύνην
θεοῦ, with both as subjective genitives. Also, justification from God would
harmonize best with the final result of the next saying in Jas. 1.21, which
derives its logical form 1.20 through διο. Jas. 1.21 most likely has a favourable judgment in view .
. . (Daniel K. Eng, Eschatological Approval: The Structure and Unifying
Motif of James [New Testament Monographs 45; Sheffield: Sheffield Phoenix,
2022], 128, italics in original)