For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms. – Ephesians 6:12
We need to remember that our enemies are not truly flesh and blood.  Our true enemy lies within the evil powers and prinicipalities of this dark world.  If someone steals from you, or harms you, it is the evil and the sin that drives those actions, which plague all of mankind.  Love your enemies as Christ first loved us.  Pray for your enemies, so there eyes may be opened and their hearts changes for eternity.