The Spirit of Sacrifice

In Romans 12:1-8, Paul urges his readers to join in the fight against the Worldly system and fully serve God and others in a spirit of unselfishness. While we honor those who have fallen in actual battle, those of us still living are called to be living sacrifices and lay down our lives for one another. So which spirit are you directed by: the spirit of selfishness or the Spirit of Sacrifice?