Righteousness
Righteousness (Hebrew ṣedeq / ṣedāqāh; Greek dikaiosynē) is the quality of being right—conformity to a norm, and so right standing and right relationship—measured ultimately by the character of God himself. The word carries both a forensic sense (a verdict of acquittal, being “in the right” before a judge) and an ethical/relational sense (covenant faithfulness lived out), and in Scripture it is regularly paired with justice (Hebrew mišpāṭ). It is one of the great unifying categories of biblical theology, running from God's own character to the standing he grants his people and the conduct he requires of them.
God is the fountain of righteousness: “The Rock, his work is perfect… just and upright is he” (Deuteronomy 32:4); “Righteous are you, O LORD, and right are your rules” (Psalm 119:137). His righteousness is not merely retributive but saving: in Isaiah it draws near as deliverance for his people—“I bring near my righteousness… and my salvation will not delay” (Isaiah 46:13; cf. Psalm 98:2). The coming Davidic king will himself bear the name “The LORD is our righteousness” (Yahweh-ṣidqēnû, Jeremiah 23:6). For human beings, righteousness means covenant loyalty expressed in worship and especially in justice toward the weak: “to do justice, and to love kindness, and to walk humbly with your God” (Micah 6:8; cf. Amos 5:24). Yet the Old Testament also exposes its absence—“no one living is righteous before you” (Psalm 143:2)—and that even Israel's best deeds are “like a polluted garment” (Isaiah 64:6). The decisive seed is sown with Abraham, who “believed the LORD, and he counted it to him as righteousness” (Genesis 15:6).
The New Testament presses the question this raises: how can sinful humans be righteous before a holy God? Jesus demands a righteousness “exceeding that of the scribes and Pharisees” (Matthew 5:20)—a matter of the heart, not mere external observance—and bids his disciples “seek first the kingdom of God and his righteousness” (Matthew 6:33). Paul announces that in the gospel “the righteousness of God is revealed… from faith for faith” (Romans 1:16–17): now, apart from the law, a righteousness from God is given through faith in Jesus Christ, who was put forward as a propitiation, so that God is both “just and the justifier of the one who has faith” (Romans 3:21–26). Like Abraham, the believer's faith is “counted as righteousness” (Romans 4:5). The exchange is summed up at the cross: “For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God” (2 Corinthians 5:21), Paul renouncing “a righteousness of my own” for that which comes through faith (Philippians 3:9).
Righteousness in Scripture is therefore both imputed—credited to the believer in justification, since Christ “became to us… righteousness” (1 Corinthians 1:30)—and imparted, the new-covenant heart on which God writes his law (Jeremiah 31:33; Ezekiel 36:26–27) and from which grows the “fruit of righteousness” (Philippians 1:11). It is at once God's gift and the shape of the redeemed life, and its final home is the new creation, “a new heaven and a new earth in which righteousness dwells” (2 Peter 3:13).