I understand that the concept of social justice is a concept which has been used to bring those in the broader Christian community in line with more redistributive political agendas. I want to avoid, for the moment, the question of whether the government's policy of playing Robin Hood is virtuous or vicious and instead deal with the abusive terminology involved in using a phrase like "social justice."
All thinking Christians ought to be deeply troubled by the term "social justice." The way the phrase is used in popular Christian circles, it should actually be called "social mercy." The confusion of justice and mercy is like confusing white and black. It's like seeing a bird and calling it a lizard. Justice and mercy, with regards to sinful human beings, are two polar opposites.
Why the shift in nomenclature? Why would someone say "white" instead of "black," or "justice" instead of "mercy"? In my estimation, it is a strategic decision. If one calls it "social mercy," the imperative nature of the problem is removed. To most, mercy is something which is important, but which is in some sense optional. However, the idea of "justice" seems imperative, because most agree that justice must always be done; otherwise we as a society are then unjust. The deceptive terminology is an attempt to gain the moral high ground so that if one opposes their idea of what social justice is, then their opponents are, by definition, defending injustice, and nobody wants to be on the wrong side of that conversation.
Perhaps the real question should first be asked. What is justice, and what is mercy? I approach this question a bit differently than some would, because I ask the question of God first. Divine justice is when God gives to the creature what he deserves. If the creature does wrong, He punishes that creature. If the creature does good, He rewards the creature. This activity is divine justice. It is giving to someone what they deserve.
What is divine mercy? Well, the simplest and shortest explanation is that it giving the creature goodness when they deserve otherwise.
Now, there should really be no massive shift between how God relates to man in terms of justice and the way that man relates to man in terms of justice. To treat each as they deserve is justice, in its simplest form. Of course there is greater complexity to this, but this complexity does not change the basic substantial meaning of what it is to be a just person (or society, which is simply a collective of individual persons) and what it is to be merciful. Even if one wants to quibble over the definitions of justice and mercy being offered, it is nearly undeniable that justice and mercy are being used interchangeably by redistributionists when the words are not, in fact, synonyms.
So then, if the terminology were honestly used, what would social justice look like? Well, frankly, it would look like the opposite of what those advocating the current definition of "social justice" say it is. In a society practicing true or literal Social Justice, each would receive according to the labor of their hands, whether that is much or little. However, the concept of "social justice" as it is pushed today reflects the opposite sentiment. It says that people should receive mercy at the hands of society, and receive goods which they did not produce or earn. There may be merits or demerits to this, but what I am simply pointing out is that the proposed policies and terminology are at odds.