Mark 10:6-12

But in the beginning, at the time of creation, ‘God made them male and female,’ as the scripture says. ‘And for this reason a man will leave his father and mother and unite with his wife, and the two will become one.’ So they are no longer two, but one. No human being then must separate what God has joined together.” When they went back into the house, the disciples asked Jesus about this matter. He said to them, “A man who divorces his wife and marries another woman commits adultery against his wife. In the same way, a woman who divorces her husband and marries another man commits adultery.”