2 Timothy 2:4 “No one serving as a soldier gets involved in civilian affairs—he wants to please his commanding officer.”
Social justice is “getting involved in civilian affairs.” What does our Commander want?
1 Timothy 6:11-12 “...pursue righteousness, godliness, faith, love, endurance and gentleness. Fight the good fight of the faith. Take hold of the eternal life to which you were called when you made your good confession in the presence of many witnesses.”
If we feed and clothe but do not speak of Jesus, we aren’t serving God, our true CINC. Feeding and clothing is great, but we need to focus on the much greater spiritual war. That includes myself, who often spends more time concerned about politics, i.e. civilian affairs, than spreading the Word—may God forgive me.
Part of the problem is that the term "social justice" is essentially undefined. It means a lot of differing things to different people.
There are principles subsumed under Christian social thinking that few on this board would argue with.
The difficulty in these discussions arises when terms go undefined and can be bastardized by the left as euphemisms for communist ideals. The left is good at redefining language like this. Just think of the way terms are used by proabortionists.