The question has been asked whether one must get divorced if one has remarried. To address this, first we have to realize that God hates it when someone sets aside (divorces) the spouse of their youth. According to Malachi, no one who deals treacherously with their spouse and sets them aside has a remnant of the Lord. Malachi 2:13-16
13 “This is another thing you do: you cover the altar of the Lord with tears, with weeping and with groaning, because He no longer regards the offering or accepts it with favor from your hand. 14 Yet you say, ‘For what reason?’ Because the Lord has been a witness between you and the wife of your youth, against whom you have dealt treacherously, though she is your companion and your wife by covenant. 15 But not one has done so who has a remnant of the Spirit. And what did that one do while he was seeking a godly offspring? Take heed then to your spirit, and let no one deal treacherously against the wife of your youth. 16 For I hate divorce,” says the Lord, the God of Israel, “and him who covers his garment with wrong,” says the Lord of hosts. “So take heed to your spirit, that you do not deal treacherously.”
Second, we must realize that Jesus was asked if it was lawful for a man to divorce his wife FOR ANY REASON. This can be taken to mean is there any reason a man can divorce his wife, or to mean can a man divorce his wife for what ever reason he can come up with. Jesus said the only acceptable reason for divorce is adultery.
Paul told people to NOT divorce an unbelieving spouse, but if the unbelieving spouse leaves, the believer is not under bondage (no longer bound by marriage). This can only be the case because it was expected that an unbelieving spouse would seek to marry someone else.
1 Corinthians 7:12-15
12 But to the rest I say, not the Lord, that if any brother has a wife who is an unbeliever, and she consents to live with him, he must not divorce her. 13 And a woman who has an unbelieving husband, and he consents to live with her, she must not send her husband away. 14 For the unbelieving husband is sanctified through his wife, and the unbelieving wife is sanctified through her believing husband; for otherwise your children are unclean, but now they are holy. 15 Yet if the unbelieving one leaves, let him leave; the brother or the sister is not under bondage in such cases, but God has called us to peace.
We know God said to not be yoked to an unbeliever (2 Corinthians 6:14), and that is often applied to say we should not marry an unbeliever. But we have explicit instructions to not set aside (initiate a divorce) an unbelieving spouse. But if we are set aside, that is, if we are divorced, by an unbeliever, then we are free from that marriage. In this case, we are no longer bound to that spouse. Having been divorced, then we are free to remarry.
Having said that, if someone says that if you have remarried, after you have divorced (regardless of whether one has biblical reasons for divorce), that you have to repent by getting divorced, this is essentially saying one must answer one sin with another sin to stop doing the first sin.
Some want to claim that remarriage after divorce is not recognized by God as a marriage, that it is adultery, but this simply is not the case. We KNOW this is not the case because we know the punishment for adultery in the old testament is death. Leviticus 20:10 ‘If there is a man who commits adultery with another man’s wife, one who commits adultery with his friend’s wife, the adulterer and the adulteress shall surely be put to death. But Deuteronomy 24:1-4 tells us remarriage is allowed after divorce, otherwise both of the people in the new marriage would be guilty of adultery and have to be put to death.
1 “When a man takes a wife and marries her, and it happens that she finds no favor in his eyes because he has found some indecency in her, and he writes her a certificate of divorce and puts it in her hand and sends her out from his house, 2 and she leaves his house and goes and becomes another man’s wife, 3 and if the latter husband turns against her and writes her a certificate of divorce and puts it in her hand and sends her out of his house, or if the latter husband dies who took her to be his wife, 4 then her former husband who sent her away is not allowed to take her again to be his wife, since she has been defiled; for that is an abomination before the Lord, and you shall not bring sin on the land which the Lord your God gives you as an inheritance.
So a certificate of divorce recognizes the relationship between the two spouses has been severed and makes it so they can marry again, with the caveat that if one has remarried, they can not divorce and remarry their original spouse. Some want to say that remarriage is spoken against by Jesus. But in fact, Jesus said if one’s spouse commits adultery, one is free to divorce and remarry. Some want to say that anyone who marries a divorced woman commits adultery. But we must take Matthew 19:3-9 (which we see above) along with Matthew 5:32, Mark 10:11-12, and Luke 16:18. The obvious exception to that is when one’s spouse adulterates the marriage covenant by committing adultery with someone else. Additionally, looking at the scriptures together, one can see that divorcing someone and marrying someone else (essentially, leaving one spouse for another) is adultery. In the same way, who ever marries someone who divorced their spouse to marry them also commits adultery – adulterating the pre-existing marriage.
18 “Everyone who divorces his wife and marries another commits adultery, and he who marries one who is divorced from a husband commits adultery.