43 “You have heard that it was said, ‘You shall love your neighbor and hate your enemy. 44 But I tell you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who mistreat you and persecute you, 45 that you may be children of your Father who is in heaven. For he makes his sun to rise on the evil and the good, and sends rain on the just and the unjust. 46 For if you love those who love you, what reward do you have? Don’t even the tax collectors do the same? 47 If you only greet your friends, what more do you do than others? Don’t even the tax collectors do the same? 48 Therefore you shall be perfect, just as your Father in heaven is perfect.
– Jesus in Matthew 5, The Sermon On the Mount