Justice for Mercy's sake has more to do with what God has been throughout all creation, for everyone, more than anyone's other cause for justice.
But what that spells is that if justice is to right the wrongs of the one that suffered through injustice, then the fact this concept is new unto many of us, is within itself an injustice coming from our part.
But there again, the return unto the one that suffered, must needs be, recieving what they were due, as we all know how much God is due, and so,, we can...