"You have heard that the law of Moses says, 'Love your neighbor' and hate your enemy.
References for Matthew 5:43
But I say, love your enemies! Pray for those who persecute you!
References for Matthew 5:44
In that way, you will be acting as true children of your Father in heaven. For he gives his sunlight to both the evil and the good, and he sends rain on the just and on the unjust, too.
If you love only those who love you, what good is that? Even corrupt tax collectors do that much.
If you are kind only to your friends, how are you different from anyone else? Even pagans do that.
References for Matthew 5:47
But you are to be perfect, even as your Father in heaven is perfect."