Mark 10:6-12

But from the beginning of creation God made them male and female. For this reason a man will leave his father and mother and be joined to his wife , and the two will become one flesh. So they are no longer two, but one flesh. Therefore what God has joined together, man must not separate.” Now in the house the disciples questioned Him again about this matter. And He said to them, “Whoever divorces his wife and marries another commits adultery against her. Also, if she divorces her husband and marries another, she commits adultery.”