Justice is the moral virtue that consists in the constant and firm will to give our due to God and neighbour. Justice towards God is called the 'virtue of religion'.
Justice towards men disposes one to respect the rights of each and to establish in human relationships the harmony that promotes equity with regard to persons and to the common good.
The just man, often mentioned in the Sacred Scriptures, is distinguished by habitual right thinking and the uprightness of his conduct toward his neighbour.
'You shall not be partial to the poor or defer to the great, but in righteousness shall you judge your neighbour.'
'Masters, treat your slaves justly and fairly, knowing that you also have a Master in heaven.'
Justice. 1. The attribute of God by which He punishes evil and rewards good. It can be called His holiness in action. (Is. 59:17-18; 28:17).Often it is put on an equal footing with God's mercy toward the helpless. (Ps. 5:8;30:2;118:40)
Justice. 2. Real intrinsic holiness that God imparts to the souls of men. This is undoubtedly Saint Paul's use of the term in Rom. 1:17; 3:21-22; 2 Cor. 5:21. Whereas the Jews thought to obtain real holiness by their own efforts in the bare observances of Mosaic rites, Paul declared that true holiness had to come from God, and faith was necessary before man could obtain it. To increase in justice (holiness, grace), good works were indispensible.