Here are some quotes from "Generous Justice," by Timothy Keller.
" Although they(people in his church) were living comfortable, safe lives, they became concerned about the most vulnerable, poor, and marginalized members of our society, and they made long-term personal sacrifices in order to serve their interests, needs, and cause. This is, according to the Bible, what it means to 'do justice.'"
"When most modern people see the word 'righteousness' in the Bible, they tend to think of it in terms of private morality, such as sexual chastity or diligence in prayer and Bible study. But in the Bible tzadeqah refers to day-to-day living in which a person conducts all relationships in family and society with fairness, generosity, and equity."
*tzadeqah is a Hebrew word that is mostly translated as "being righteous," but should be translated as "being just".
"We do justice when we give all human beings their due as creations of God. Doing justice includes not only the righting of wrongs, but generosity and social concern, especially toward the poor and vulnerable. This kind of life reflects the character of God. It consists of a broad range of activities, from simple fair and honest dealings with people in daily life, to regular, radically generous giving of your time and resources, to activism that seeks to end particular forms of injustice, violence, and oppression."