In 419 BC, during the height of Athens' war with Sparta, one of Athens' holdings, the Island city of Mitylene revolted.  The men of Athens were so furious that Mitylene would take this inopportune time to rebel that they dispatched a sizeable fleet to kill all the males of Mitylene and to bring all the women back as slaves.  Shortly after the fleet departed, the men of Athens reconsidered their decision.  They realized that such harshness was typical of Sparta, not of more enlightened Athens, and so they sent their swiftest rowers to overtake the fleet, and prevent the wholesale slaughter of the men of Mitylene.  At the eleventh hour, on the eve of the Athenians attack, they received news that their original orders had been rescinded, and although rebellion was suppressed, the city was spared.

            Three years later, during the winter of 416-415 BC, when the war was going badly for Athens, they set their sights on the island of Melos.  Melos had once been a colony of Sparta, but now was independent, and non-aggressive.  Their island would provide an advantageous base of operations against nearby Sparta, though, and Athens sent a large fleet there with the demand that the people of Melos surrender their island to them.  The Melians offered to sign a non-aggression pact with Athens, and to be good hosts to anyone Athens might send to their island, but they would not surrender their independence to anyone.  So the Athenians slaughtered all the men, and carried the women back to Athens as slaves.

            When things were going fairly well for the Athenians, they took great pains to act based upon their values.  When their fortunes were not so fair, they acted solely on the basis of self-interest.  History teaches us over and over again that the result of naked self-interest will be brutality, usually against the innocent.

            What is true of nations is true of persons as well, the Bible teaches us that.  The murder of Abel, the selling of Joseph, the rape of Tamar, the stoning of Stephen - every act of aggression we can think of from the Bible - even the crucifixion of Jesus, was not a random act, but the result of calculated self-interest.  And so, the Bible is careful to frequently remind us:

Do nothing from selfishness, or empty conceit, but with humility of mind let each of you regard one another as more important than himself.  Philippians 2.3
Be devoted to one another in brotherly love; give preference to one another in honor.  Romans 12.10
Whoever wishes to be first among you must be the slave of all.  For even the Son of Man did not come to be served, but to serve, and give his life a ransom for many.  Mark 10.44-45.

            Since doing "what is best for me" comes as easily to us as breathing in and out, it is important to remember these verses.  It is important to remember that self-interest isn't "what's best for me". What is truly best for any of us is to be right with God and our God "opposes the proud, but gives grace to the humble" (Isaiah 57.15, James 4.6, 1 Peter 5.5).