The Greek dikaiosyne is one of the central theological terms of the New Testament, meaning righteousness, justice, or right standing. It denotes both the character of being right (morally upright) and the legal status of being declared right (justified).
Dikaiosyne is the master concept of Paul's letters to Rome and Galatia. Romans 1:17 — 'For in the gospel the righteousness of God is revealed' — announces a dikaiosyne that is not human achievement but divine gift: 'the righteousness of God through faith in Jesus Christ for all who believe' (Romans 3:22). This 'alien righteousness' — Christ's right standing credited to the believer — is the theological heart of justification. The Beatitudes pronounce blessing on those who 'hunger and thirst for dikaiosyne' (Matthew 5:6), affirming that righteousness is something we lack and desperately need. The eschatological hope of 2 Peter 3:13 is a 'new heaven and a new earth where dikaiosyne dwells' — a world where everything is finally, completely right.