Social justice, according to Wikipedia, “is justice in relation to the distribution of wealth, opportunities, and privileges within a society where individuals’ rights are recognized and protected.”
Listen to the words of Jesus in Matthew 25:41-46:
“Then he will say to those at his left hand, ‘You who are accursed, depart from me into the eternal fire prepared for the devil and his angels, for I was hungry and you gave me no food, I was thirsty and you gave me nothing to drink, I was a stranger and you did not welcome me, naked and you did not give me clothing, sick and in prison and you did not visit me.’ Then they also will answer, ‘Lord, when was it that we saw you hungry or thirsty or a stranger or naked or sick or in prison and did not take care of you?’ Then he will answer them, ‘Truly I tell you, just as you did not do it to one of the least of these, you did not do it to me.’) Then he will answer them, ‘Truly I tell you, just as you did not do it to one of the least of these, you did not do it to me.’ And these will go away into eternal punishment but the righteous into eternal life.”
Social justice is a moral obligation for all Christians. This is justice, not only for those that are Christians, but for all people. This is part of loving our neighbor as ourselves. It’s about being God-like, for “God so loved the world” (John 3:16). Not just Christians!