If anything happens contrary to God's will, it is unjust (by definition). The way Protestants see it, man's Fall, then, was not (could not be) against His will and therefore is not an injustice to God that requires justice.
" The way Protestants see it, man's Fall, then, was not (could not be) against His will and therefore is not an injustice to God that requires justice."
Justice has to do with rewards or punishment according to what one merits. Man can't perform an injustice to God for he can't reward God or punish God. Man's fall was according to the plan and purpose of God and his redemption is according to the plan and purpose of God. There is no injustice here. Those that will perish will do so according to the plan of God and according to their own will. None will say, "if only I knew I would change my mind." Revelation is clear that they will curse God, try to hide from God, and will choose to be buried under avalanches rather than submit to God. They are content to die eternally worshiping the god of their own choosing; SELF!