In Matthew 5 and Luke 6 we see that we are called to love our enemies. In 1 Corinthians 13 we're told what love is.

Be patient to your enemy
Be kind to your enemy
Do not think yourself better than your enemy
Do not be rude to your enemy
Look out for your enemy's concerns
Do not be easily angered by your enemies
Hold no grudges against your enemy
When your enemy suffers, find no pleasure in it
When your enemy is joyous, share in that joy
Protect your enemy
Trust your enemy
Have hope in your enemy
Finally, always love your enemy, to the end

Matthew 5:38-41, Matthew 5:43-44, Matthew 5:46-47, Luke 6:27-30, Luke 6:32-33, Luke 6:35-36 and 1 Corinthians 13:4-7