In The Oresteia, after Orestes is bidden by the god Apollo to kill his mother, the gods known as the Furies sentence him to be haunted. Due to the opposition of the wills of the gods, there was a divine trial, and the outcome was to be wagered by a jury of twelve men and the court's judge, the wisest goddess Athena. The nature of conflicting divinity clearly defines the line between devotion (on Orestes" part) and justice (the argument of the Furies, that the murder was still a wrongful act, even if divinely decreed). They can be further characterized into two sub-categories: the devotion being the humanly element of the matter--because it comes down to a personal choice--and the divine matter of the subject, justice, because that comes from the gods.
This story is ultimately based upon our primitive conception of what we think could be right and wrong. The gods are simply the catalyst to propel the true goal of the story: what is just and unjust. Similarly, if murdering is unjust, then why does punishment come in differing severities, if it even comes at all? While most punishment today for murder is jail or execution, the concept of The Oresteia is what occurs if a person goes unpunished by society, which is the approach that I will henceforth take.
The ultimate goal of The Oresteia is to apply what are primarily our views of right and wrong to a given circumstance, and see if, in that given circumstance, a fundamentally wrong act is actually justifiable and therefore perhaps, even, right. So "Thou shalt not kill," vague intentionally, is now put to the test, and given the platform to showcase so fine a line between the two that we still grapple to this very day with what is truly right or wrong.
In war, we send over soldiers to kill our enemies. The soldiers are stripped of any freedom to think that they may be going against a moral standard. Though we are taught that killing is wrong, and punished if we ever do kill, soldiers are dumped in a new reality where killing is suddenly promoted.