In Matthew 19:9, Jesus teaches that one who sends his wife away and marries another commits adultery, because what God has joined together, man may not separate. He upholds the sanctity of marriage, even when a man then marries another woman. This is why God sees that next marriage also as adultery, so most manuscripts also contain a statement in Matthew 19:9 about the guilt of the man who marries a divorced woman. He also is guilty of adultery, in marrying another’s wife. Jesus thus says that no certificate of divorce ends a marriage, except in the case of sexual immorality. In other words, when a spouse commits adultery, the divorce has, in effect, already taken place. Both Matthew 19:9 and Matthew 5:32 allow divorce on account of adultery, but what Matthew 19:9 implies goes beyond Matthew 5:32. The latter verse speaks of being complicit in the adulterous second marriage of another person, while Matthew 19:9 speaks of one who is himself guilty of wrongly entering into a second marriage.
In Matthew 19:9, Jesus teaches that someone who sends his wife away and marries another commits adultery, and he grounds this in the fact that what God has joined together, man may not separate. He upholds the sanctity of marriage, even in cases when a man goes on to marry another woman. This is why God regards that second marriage as a form of adultery. Most manuscripts therefore also contain a statement here in Matthew 19:9 concerning the guilt of the man who marries a divorced woman. He is also guilty of adultery, for he marries the wife of another. Jesus thereby teaches that no certificate of divorce has the power to end the marriage, with sexual immorality being the only exception to the rule. In other words, when a spouse commits adultery, the divorce has, in effect, already taken place. At the very least, both Matthew 19:9 as well as Matthew 5:32 permit divorce on account of adultery, even if not expressly mentioned. At the same time, Matthew 19:9 does say something implicitly that goes beyond Matthew 5:32. The latter verse speaks about being complicit in the adulterous second marriage of another person. Matthew 19:9, however, speaks about a person who is himself guilty of illegitimately entering into a second marriage.1
9 And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.”