Did Jesus allow for divorce in the event a spouse commits adultery?

Someone asked me about the "except for adultery" clause that Jesus makes regarding when divorce is allowed. Many people over the centuries have though that Jesus was indeed making one sole exception to the permanence of marriage. They understandably ready this clause as if Jesus were saying you can end your marriage if your spouse commits adultery. But the Catholic Church explains this "except for adultery" in a way that pays attention to the actual words of Jesus. And this is how the Church Fathers who comment on this "except" clause also interpret it. At the Ecumenical Council of Florence, the Church gave an official explanation:

The seventh is the sacrament of matrimony, which is a sign of the union of Christ and the church according to the words of the apostle: This sacrament is a great one, but I speak in Christ and in the church. The efficient cause of matrimony is usually mutual consent expressed in words about the present. A threefold good is attributed to matrimony. The first is the procreation and bringing up of children for the worship of God. The second is the mutual faithfulness of the spouses towards each other. The third is the indissolubility of marriage, since it signifies the indivisible union of Christ and the church. Although separation of bed is lawful on account of fornication, it is not lawful to contract another marriage, since the bond of a legitimately contracted marriage is perpetual.

In brief, Jesus allows for a spouse to live in a separate dwelling space if one spouse has committed fornication. But even if separated, they remain married. Divorce merely means living separately, as if single. The sin only comes about if one of those separated spouses tries to enter another marriage.

Consider the actual words of Jesus:

• Matthew 5:31 “It was also said [by Moses], ‘Whoever divorces his wife, let him give her a certificate of divorce.’ 32 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.

• Matthew 19: 7 They said to him, “Why then did Moses command one to give a certificate of divorce and to send her away?” 8 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. 9 And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.”

• Mark 10:11 And he said to them, “Whoever divorces his wife and marries another commits adultery against her, 12 and if she divorces her husband and marries another, she commits adultery.”

• Luke 16:18 “Everyone who divorces his wife and marries another commits adultery, and he who marries a woman divorced from her husband commits adultery.

• 1 Cor 7:10 To the married I give this charge (not I, but the Lord): the wife should not separate from her husband 11 (but if she does, she should remain unmarried or else be reconciled to her husband), and the husband should not divorce his wife.   

Notice the repeated use of the clause "and marries another". Without the "and marries another," there is no adultery. A divorce in and of itself doesn't cause adultery. Paul's explanation above also vindicates the Catholic view: separation is ok, but remarriage is not. So we can see the official Catholic reading elegantly preserves the dignity and permanence of marriage, while also easily explaining the "except" clause. I don't know of many other groups out there that have that kind of skill when it comes to exegesis. In fact, most people are oblivious to this understanding of the text.

Next, notice that of the four times divorce is talked about in the New Testament, only Matthew includes an "except" clause. That should suggest that the "except" clause is not really to be taken as a loophole. In fact, it would be kind of insane for Jesus to point back to the beginning of Creation and speak of the permanence of marriage, only to allow for a giant loophole. People would be committing adultery all the time if it meant getting out of a marriage they didn't like. That totally undermines the goal of Jesus rebuking the Pharisees.

For a detailed look at all the available Church Fathers and Councils and Documents on this issue, see THIS ARTICLE at Called To Communion. It's an excellent apologetics article, though it is very long to read.