The Bible refers to Christians as pilgrims.  This is because we are not citizens of this world, but citizens of heaven and just passing through.  As pilgrims we are called to not hate and despise those that may despise us as enemies.  We are to love our enemies and do what they cannot do.  But, they love those that love them and those that are gracious to them.  Jesus reminds us in this passage that pilgrims aren't to be bitter, unforgiving or seek vengeance but to be gracious and merciful even to those who despise.  The result may be that they may experience this love from us and no longer be an enemy.  This may result in Christians showing more love by giving them the Gospel of Christ.  

Primary Scripture: Luke 6:32-42