So, what exactly is "social justice" in the Biblical sense of the term?

I found this website:  http://www.gotquestions.org/social-justice.html and within its explanation, it refers to various Scripture, including the oft-cited "love your neighbor as yourself."

Quoting from the New International version, Matthew 22:36-40:  "Teacher, which is the greatest commandment in the Law?"  Jesus replied:  " 'Love the Lord your God with all your heart and with all your soul and with all your mind.  This is the first and greatest commandment.  And the second is like it: 'Love your neighbor as yourself.'  All the Law and the Prophets hang on these two commandments.' "

For a long time whenever I heard or read this passage, I thought it was just telling me to love the Lord completely.  But then one day the emphasis changed and it suddenly became a commandment that was telling me to, yes, love the Lord completely, but more precisely to love Him with all of my own heart, soul and mind, at which point "And love your neighbor as yourself" became "And leave everyone else to do the same."

It made perfect sense to me, too--because I was taught that God wants each of us to have our own personal relationship with Him, and in the process of developing that relationship with Him, we're not always, or necessarily ever, going to be exactly where anyone else is in their journey to Him or their relationship with Him, and that's fine with Him, and it should be fine with everyone else and would be fine with everyone else IF we loved everyone else enough to leave them as free to develop their own personal relationship with God as we want to be. ("Love your neighbor as yourself.")

This doesn't mean that we can't share our personal testimony with others.  It just means that we shouldn't judge others who don't believe exactly as we do.  Indeed, the Book of Matthew as a whole says a lot about judging others and hypocrites.