Biblically to "bring justice" does not mean to bring punishment, but to bring healing and reconciliation. Justice means to make things right. All through the Prophets justice is associated with caring for others, as something that is not in conflict with mercy, but rather an expression of it. Biblically, justice is God's saving action at work for all that are oppressed:
"Learn to do right! Seek justice, encourage the oppressed. Defend the cause of the fatherless, plead the case of the widow". (Isaiah 1:17)The way that we "administer justice", the Prophets tell us, is by encouraging and helping the oppressed. In contrast to what the Satisfaction-Doctrine says, God's justice is not in conflict with his mercy, they are inseparable. True justice can only come though mercy.
"This is what the LORD says: "`Administer justice every morning; rescue from the hand of his oppressor the one who has been robbed" (Jeremiah 21:12)
"This is what the LORD Almighty says: `Administer true justice: show mercy and compassion to one another. (Zechariah 7:9)If we want to understand the concept of justice as the writers of the Old Testament did, then we must see it as a "setting things right again". Thus when Christ comes, the way that he brings about justice is through mercy and compassion. Notice how in this next verse Christ does not bring justice with a hammer, but with a tenderness that cares for the broken and the abused.
"Yet the LORD longs to be gracious to you; he rises to show you compassion. For the LORD is a God of justice".( Isaiah 30:18)
"I will put my Spirit on him, and he will proclaim justice to the nations… A bruised reed he will not break, and a smoldering wick he will not snuff out, till he leads justice to victory" (Matthew 12:18-21)The way that God brings about justice and "leads it to victory" is through acts of compassion - sheltering the "smoldering wick", and the "bruised reed". And what does Christ "proclaim to the nations" to bring about this justice?
"He has sent me to proclaim freedom for the prisoners and recovery of sight for the blind, to release the oppressed, to proclaim the year of the Lord's favor." (Luke 4:18-19)The justice that Jesus ushers in, the righteousness he brings, have to do with God pouring his love out on us, with God showing his compassion for the lost and the poor. With God meeting us in our need and liberating us from sin and oppression. With "setting things right" - that is what biblical justice is about. There is no dichotomy between a "God of justice" in the Old Testament and a "God of mercy" in the New. There is no split in God's character. God has always been a compassionate God, a God of love. Jesus reveals who God is and who God has always been. Justice is about mercy. Justice comes through mercy and always has.