Revenge is not justice, but retaliation for acts done against one.
Justice is a legal treatment of acts/words etc against an offender.
Not all justice is retributive justice, i.e. justice against an offender; if someone takes what belongs to you and the courts restore what was taken, that is also justice. Justice is not merely
against, justice is also
for. In fact justice, biblically, is usually restorative justice, justice
for the mistreated and the oppressed.
When MLK said peace requires a just society he is not referring to "getting the bad guys" he is referring to a society that treats all people with fairness and equity.
Thinking of justice as only retribution misses, indeed utterly fails to grasp, one of the most essential teachings of Scripture--namely that we have been freely justified by God's grace. Luther's breakthrough, as it were, was when reading the Scriptures when reading Romans 1:17, "For in [the Gospel] the justice of God is revealed from faith for faith, as it is written, 'the just shall live by faith'" With this Luther understood that the justice of God is not the justice which punishes sins or condemns people, this is the justice by which God makes sinners just through faith; the justice which is from God, in Christ, imputed to us, by which we are made just. The Gospel does not reveal an angry God of retribution and wrath, but the loving and kind God who saves sinners through His Son, the God of grace, mercy, and love. This is the cornerstone of the Reformation.
-CryptoLutheran