“Furthermore it has been said, ‘Whoever divorces his wife, let him give her a certificate of divorce.’ But I say to you that whoever divorces his wife for any reason except sexual immorality causes her to commit adultery; and whoever marries a woman who is divorced commits adultery.
“Again you have heard that it was said to those of old, ‘You shall not swear falsely, but shall perform your oaths to the Lord.’ But I say to you, do not swear at all: neither by heaven, for it is God’s throne; nor by the earth, for it is His footstool; nor by Jerusalem, for it is the city of the great King. Nor shall you swear by your head, because you cannot make one hair white or black. But let your ‘Yes’ be ‘Yes,’ and your ‘No,’ ‘No.’ For whatever is more than these is from the evil one.
“You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ But I tell you not to resist an evil person. But whoever slaps you on your right cheek, turn the other to him also. If anyone wants to sue you and take away your tunic, let him have your cloak also. And whoever compels you to go one mile, go with him two. Give to him who asks you, and from him who wants to borrow from you do not turn away.”
– Matthew 5:31-42