God hates divorce
"Another thing you do: You flood the LORD’s altar with tears. You weep and wail because he no longer pays attention to your offerings or accepts them with pleasure from your hands. You ask, "Why?" It is because the LORD is acting as the witness between you and the wife of your youth, because you have broken faith with her, though she is your partner, the wife of your marriage covenant. Has not the LORD made them one? In flesh and spirit they are his. And why one? Because he was seeking godly offspring. So guard yourself in your spirit, and do not break faith with the wife of your youth. "I hate divorce," says the LORD God of Israel, "and I hate a man’s covering himself with violence as well as with his garment," says the LORD Almighty. So guard yourself in your spirit, and do not break faith" (Malachi 2:13-16).
Jesus says: No divorce, except in the case of adultery
"It has been said, ‘Anyone who divorces his wife must give her a certificate of divorce.’ But I tell you that anyone who divorces his wife, except for marital unfaithfulness, causes her to become an adulteress, and anyone who marries the divorced woman commits adultery" (Matthew 5:31-32).
"Haven’t you read," he replied, "that at the beginning the Creator ‘made them male and female,’ and said, ‘For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh’? So they are no longer two, but one. Therefore what God has joined together, let man not separate" (Matthew 19:4-6).
Husband and wife are bound together until death separates them
"Do you not know, brothers—for I am speaking to men who know the law—that the law has authority over a man only as long as he lives? For example, by law a married woman is bound to her husband as long as he is alive, but if her husband dies, she is released from the law of marriage. So then, if she marries another man while her husband is still alive, she is called an adulteress. But if her husband dies, she is released from that law and is not an adulteress, even though she marries another man" (Romans 7:1-3).
A believer may not initiate a divorce from an unbelieving spouse
"To the married I give this command (not I, but the Lord): A wife must not separate from her husband. But if she does, she must remain unmarried or else be reconciled to her husband. And a husband must not divorce his wife. To the rest I say this (I, not the Lord): If any brother has a wife who is not a believer and she is willing to live with him, he must not divorce her. And if a woman has a husband who is not a believer and he is willing to live with her, she must not divorce him. For the unbelieving husband has been sanctified through his wife, and the unbelieving wife has been sanctified through her believing husband. Otherwise your children would be unclean, but as it is, they are holy. But if the unbeliever leaves, let him do so. A believing man or woman is not bound in such circumstances; God has called us to live in peace. How do you know, wife, whether you will save your husband? Or, how do you know, husband, whether you will save your wife?" (1 Corinthians 7:10-16).
If the unbelieving spouse wants to depart, he or she may do so
"But if the unbeliever leaves, let him do so. A believing man or woman is not bound in such circumstances; God has called us to live in peace" (1 Corinthians 7:15).