“It was also said, ‘Whoever divorces his wife, let him give her a certificate of divorce.’  But I say to you that everyone who divorces his wife, except on the ground of sexual immorality, makes her commit adultery, and whoever marries a divorced woman commits adultery.
 And Pharisees came up to him and tested him by asking, “Is it lawful to divorce one’s wife for any cause?”  He answered, “Have you not read that he who created them from the beginning made them male and female,  and said, ‘Therefore a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh’?  So they are no longer two but one flesh. What therefore God has joined together, let not man separate.”  They said to him, “Why then did Moses command one to give a certificate of divorce and to send her away?”  He said to them, “Because of your hardness of heart Moses allowed you to divorce your wives, but from the beginning it was not so.  And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.”  The disciples said to him, “If such is the case of a man with his wife, it is better not to marry.”  But he said to them, “Not everyone can receive this saying, but only those to whom it is given.  For there are eunuchs who have been so from birth, and there are eunuchs who have been made eunuchs by men, and there are eunuchs who have made themselves eunuchs for the sake of the kingdom of heaven. Let the one who is able to receive this receive it.”
 And Pharisees came up and in order to test him asked, “Is it lawful for a man to divorce his wife?”  He answered them, “What did Moses command you?”  They said, “Moses allowed a man to write a certificate of divorce and to send her away.”  And Jesus said to them, “Because of your hardness of heart he wrote you this commandment.  But from the beginning of creation, ‘God made them male and female.’  ‘Therefore a man shall leave his father and mother and hold fast to his wife,  and the two shall become one flesh.’ So they are no longer two but one flesh.  What therefore God has joined together, let not man separate.”  And in the house the disciples asked him again about this matter.  And he said to them, “Whoever divorces his wife and marries another commits adultery against her,  and if she divorces her husband and marries another, she commits adultery.”
1 Corinthians 7:10–24
 To the married I give this charge (not I, but the Lord): the wife should not separate from her husband  (but if she does, she should remain unmarried or else be reconciled to her husband), and the husband should not divorce his wife.
 To the rest I say (I, not the Lord) that if any brother has a wife who is an unbeliever, and she consents to live with him, he should not divorce her.  If any woman has a husband who is an unbeliever, and he consents to live with her, she should not divorce him.  For the unbelieving husband is made holy because of his wife, and the unbelieving wife is made holy because of her husband. Otherwise your children would be unclean, but as it is, they are holy.  But if the unbelieving partner separates, let it be so. In such cases the brother or sister is not enslaved. God has called you to peace.  For how do you know, wife, whether you will save your husband? Or how do you know, husband, whether you will save your wife?
 Only let each person lead the life that the Lord has assigned to him, and to which God has called him. This is my rule in all the churches.  Was anyone at the time of his call already circumcised? Let him not seek to remove the marks of circumcision. Was anyone at the time of his call uncircumcised? Let him not seek circumcision.  For neither circumcision counts for anything nor uncircumcision, but keeping the commandments of God.  Each one should remain in the condition in which he was called.  Were you a bondservant when called? Do not be concerned about it. (But if you can gain your freedom, avail yourself of the opportunity.)  For he who was called in the Lord as a bondservant is a freedman of the Lord. Likewise he who was free when called is a bondservant of Christ.  You were bought with a price; do not become bondservants of men.  So, brothers, in whatever condition each was called, there let him remain with God.
1 Corinthians 7:39
 A wife is bound to her husband as long as he lives. But if her husband dies, she is free to be married to whom she wishes, only in the Lord.