I would hold that the Bible teaches that in all cases where there is a living lawful1 spouse, it is adultery to remarry.
If allowance for remarriage is given for unfaithfulness, based on the Mat 19:9 exception that is found in the Textus Receptus (TR) and in most translations, then all a person must do is backslide and commit adultery and then you have an excuse for remarriage.
Or the person could just get married to their second spouse and consummate the marriage. This would be considered adultery, and now they can lawfully1 be remarried while they have a living spouse from a lawful1 marriage. Then they would redo their vows just in case the Lord did not accept the first vows because they had not committed adultery yet.
Some hold that Mat 19:9 only provides the right of remarriage for the innocent party. It makes no sense to say innocent-party remarriage is ok because it is not adultery for them, since they are no longer married in the eyes of the Lord. If the innocent party is no longer married in the eyes of the Lord, then clearly the guilty party is no longer either. The only reason remarriage could be adultery for the guilty party is because they have a lawful1 spouse. It is not possible for the guilty party to have a lawful1 spouse and the innocent party not to have a lawful1 spouse, thus the innocent party having the right to remarriage while the guilty party holds no logic.
So, we are back to the position that Jesus left divorce and remarriage wide open. Well, in Jesus’ time it was already wide open, so we have to explain why the disciples were so surprised and thought perhaps it was better off not to get marriage at all (Mat 10:10).
When I read through all the scriptures in the New Testament concerning remarriage, I just do not see any room at all for remarriage. The following are the scriptures that deal with remarriage in the New Testament.
For Mat 19:9, I have also put in the KJV, the Textus Receptus Greek, and McFall’s version which is translated without the influence of εἰ in the Textus Receptus Greek (εἰ μὴ ἐπὶ πορνείᾳ) from which the KJV came from.
Mat 19:9 (KJV) And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery.
Mat 19:9 (McFall) Now I say to you that who, for example, may have divorced his wife–he may not have divorced her for fornication–and may have married another woman, he becomes adulterous by marrying her.
Mat 19:9 (NA27): λέγω δὲ ὑμῖν ὅτι ὃς ἂν ἀπολύσῃ τὴν γυναῖκα αὐτοῦ μὴ ἐπὶ πορνείᾳ καὶ γαμήσῃ ἄλλην μοιχᾶται
Mar 10:11, 12 (KJV) And he saith unto them, Whosoever shall put away his wife, and marry another, committeth adultery against her. And if a woman shall put away her husband, and be married to another, she committeth adultery.
Luk 16:18 (KJV) Whosoever putteth away his wife, and marrieth another, committeth adultery: and whosoever marrieth her that is put away from her husband committeth adultery.
Rom 7:2, 3 (KJV) For the woman which hath an husband is bound by the law to her husband so long as he liveth; but if the husband be dead, she is loosed from the law of her husband. So then if, while her husband liveth, she be married to another man, she shall be called an adulteress: but if her husband be dead, she is free from that law; so that she is no adulteress, though she be married to another man.
1Co 7:10, 11 (KJV) And unto the married I command, yet not I, but the Lord, Let not the wife depart from her husband: But and if she depart, let her remain unmarried, or be reconciled to her husband: and let not the husband put away his wife.
1Co 7:39 (KJV) The wife is bound by the law as long as her husband liveth; but if her husband be dead, she is at liberty to be married to whom she will; only in the Lord.
Following are the most popular reasons that people give for remarriage or staying in a second marriage while they already have a lawful1 living spouse:
1. The exception clause of Mat 19:9 in the case of unfaithfulness of the other party.
2. The Pauline permission of 1Cor 7:15 for the case of abandonment.
3. You get a new slate when you are saved.
4. To separate a second marriage is wrong and causes more harm.
5. It is not fair that the innocent party suffers for the sin of the guilty party.
6. The sin is only in the act of remarrying, not in copulating, therefore you can repent for the act of remarriage and stay together.
7. We are all sinners anyway and our sins are forgiven – past, present and future.
I may do a more detailed post some time soon that goes over the above popular reasons.
1The use of lawful is in respect to the new covenant law (the law of liberty, the royal law) and is not referring to the law of Moses or the current marriage laws of any nation.