From the Gospel according to Matthew
MT 5:38-48

Jesus said to his disciples: “You have heard that it was said, An eye for an eye and a tooth for a tooth.  But I say to you, offer no resistance to one who is evil.  When someone strikes you on your right cheek, turn the other one as well.  If anyone wants to go to law with you over your tunic, hand over your cloak as well.  Should anyone press you into service for one mile, go for two miles.  Give to the one who asks of you, and do not turn your back on one who wants to borrow.

“You have heard that it was said, You shall love your neighbor and hate your enemy.  But I say to you, love your enemies and pray for those who persecute you, that you may be children of your heavenly Father, for he makes his sun rise on the bad and the good, and causes rain to fall on the just and the unjust.  For if you love those who love you, what recompense will you have? Do not the tax collectors do the same?  And if you greet your brothers only, what is unusual about that?  Do not the pagans do the same? So be perfect, just as your heavenly Father is perfect.”