Marriage and Divorce in the New Testament, Part VIII: Divorce/Abandonment and the One Flesh Union

When Jesus gives the basis for His argument to the Pharisees in the Synoptics, He states that the man and the woman have become one flesh, and in fact, have been joined together into one flesh by God Himself. This one flesh union is what constitutes marriage. This union is not to be separated in the eyes of men, referring to divorce.

What one must believe, however, is that either abandonment in marriage, or certainly a divorce/abandonment ending the marriage, would actually break the one flesh union, so that the parties are now free to marry other people.

If the one flesh union is still intact after abandonment during marriage or in the act of getting a divorce (the words for divorce and abandonment/leaving, etc. are the same words), then to marry another person is to commit adultery, whether one has secured a divorce from men or not.

The texts actually help us in determining whether the one flesh union is broken by abandonment/divorce. In Matthew 5:31-32, Jesus states:

Ἐρρέθη δέ· ὃς ἂν ἀπολύσῃ τὴν γυναῖκα αὐτοῦ, δότω αὐτῇ ἀποστάσιον. ἐγὼ δὲ λέγω ὑμῖν ὅτι πᾶς ὁ ἀπολύων τὴν γυναῖκα αὐτοῦ παρεκτὸς λόγου πορνείας ποιεῖ αὐτὴν μοιχευθῆναι, καὶ ὃς ἐὰν ἀπολελυμένην γαμήσῃ, μοιχᾶται.

You have heard, "Whoever would divorce his wife, let him give her a notice of abandonment." But I say to you that anyone who abandons his wife, except in the case of an illegitimate union, makes her commit adultery, and whoever marries an abandoned woman commits adultery.

Notice two things here. Abandonment precedes the marriage to another. Yet, this did not break the one flesh union, and therefore, the woman is viewed as committing adultery. Likewise, a man who marries a woman who has been abandoned commits adultery. If the one flesh union is broken by abandonment/divorce, neither party would be guilty of adultery, as they would be no longer tied to their previous spouse. However, Jesus says that they are guilty of it, indicating that the one flesh union is still in force.

Likewise, in Matthew 19:3-9, the same logic plays out due to the one flesh union that God has created between the couple.

Καὶ προσῆλθον αὐτῷ Φαρισαῖοι πειράζοντες αὐτὸν καὶ λέγοντες· εἰ ἔξεστιν ἀνθρώπῳ ἀπολῦσαι τὴν γυναῖκα αὐτοῦ κατὰ πᾶσαν αἰτίαν;
ὁ δὲ ἀποκριθεὶς εἶπεν· οὐκ ἀνέγνωτε ὅτι ὁ κτίσας ἀπ᾽ ἀρχῆς ἄρσεν καὶ θῆλυ ἐποίησεν αὐτούς;
καὶ εἶπεν· ἕνεκα τούτου καταλείψει ἄνθρωπος τὸν πατέρα καὶ τὴν μητέρα καὶ κολληθήσεται τῇ γυναικὶ αὐτοῦ, καὶ ἔσονται οἱ δύο εἰς σάρκα μίαν.
ὥστε οὐκέτι εἰσὶν δύο ἀλλὰ σὰρξ μία. ὃ οὖν ὁ θεὸς συνέζευξεν ἄνθρωπος μὴ χωριζέτω.
Λέγουσιν αὐτῷ· τί οὖν Μωϋσῆς ἐνετείλατο δοῦναι βιβλίον ἀποστασίου καὶ ἀπολῦσαι [αὐτήν];
λέγει αὐτοῖς ὅτι Μωϋσῆς πρὸς τὴν σκληροκαρδίαν ὑμῶν ἐπέτρεψεν ὑμῖν ἀπολῦσαι τὰς γυναῖκας ὑμῶν, ἀπ᾽ ἀρχῆς δὲ οὐ γέγονεν οὕτως.
λέγω δὲ ὑμῖν ὅτι ὃς ἂν ἀπολύσῃ τὴν γυναῖκα αὐτοῦ μὴ ἐπὶ πορνείᾳ καὶ γαμήσῃ ἄλλην μοιχᾶται.

And the Pharisees came to Him, testing Him and saying whether it is permitted for a man to divorce/abandon his wife for any reason. But answering, He said, "Have you not read that the Creator from the beginning made them male and female? And He said, 'For this reason a man will leave his father and mother and cling to his wife; and the two will become one flesh'." Therefore, they are no longer two, but one flesh. Therefore, that which God has joined together no human is to separate/grant a divorce. 
They said to Him, "Why, then, did Moses command to give a certificate of abandonment and to divorce [her]?"
He said to them, "Because Moses, in the face of your rebellion, permitted you to abandon your wives, but from the beginning, it was not meant to be like this. Now, I say to you that whoever abandons his wife, not concerning an illegitimate union, and marries another woman commits adultery.

Mark, from whom Matthew is drawing, is even clearer.

Καὶ προσελθόντες Φαρισαῖοι ἐπηρώτων αὐτὸν εἰ ἔξεστιν ἀνδρὶ γυναῖκα ἀπολῦσαι, πειράζοντες αὐτόν.
ὁ δὲ ἀποκριθεὶς εἶπεν αὐτοῖς· τί ὑμῖν ἐνετείλατο Μωϋσῆς;
οἱ δὲ εἶπαν· ἐπέτρεψεν Μωϋσῆς βιβλίον ἀποστασίου γράψαι καὶ ἀπολῦσαι.
ὁ δὲ Ἰησοῦς εἶπεν αὐτοῖς· πρὸς τὴν σκληροκαρδίαν ὑμῶν ἔγραψεν ὑμῖν τὴν ἐντολὴν ταύτην.
ἀπὸ δὲ ἀρχῆς κτίσεως ἄρσεν καὶ θῆλυ ἐποίησεν αὐτούς·
ἕνεκεν τούτου καταλείψει ἄνθρωπος τὸν πατέρα αὐτοῦ καὶ τὴν μητέρα [καὶ προσκολληθήσεται πρὸς τὴν γυναῖκα αὐτοῦ],
καὶ ἔσονται οἱ δύο εἰς σάρκα μίαν· ὥστε οὐκέτι εἰσὶν δύο ἀλλὰ μία σάρξ.
ὃ οὖν ὁ θεὸς συνέζευξεν ἄνθρωπος μὴ χωριζέτω.
Καὶ εἰς τὴν οἰκίαν πάλιν οἱ μαθηταὶ περὶ τούτου ἐπηρώτων αὐτόν.
καὶ λέγει αὐτοῖς· ὃς ἂν ἀπολύσῃ τὴν γυναῖκα αὐτοῦ καὶ γαμήσῃ ἄλλην μοιχᾶται ἐπ᾽ αὐτήν·
καὶ ἐὰν αὐτὴ ἀπολύσασα τὸν ἄνδρα αὐτῆς γαμήσῃ ἄλλον μοιχᾶται.

And the Pharisees were coming, asking Him whether it was acceptable for a husband to divorce/abandon a wife, testing Him.  
But answering, He said to them, "What did Moses command you?"
And they said, "Moses permitted a certificate of divorce to be written and to divorce/abandon."
And Jesus said, "In light of your rebellion he wrote this commandment to you; but from the beginning of creation He made them male and female. For this reason a man will leave his father and mother [and cling to his wife] and the two will turn into one flesh. Hence, they are no longer two but one flesh. Therefore, what God has joined together no human is to separate. 
And going up into the house, the disciples questioned Him concerning this. 
And He said to them, "Whoever divorces/abandons his wife and marries another woman commits adultery against her; and if she divorces/abandons her husband [and] marries another man, she commits adultery.

Again, we see that abandonment/divorce precedes the adultery, and it is an adultery ἐπ᾽ αὐτήν "against her." Likewise, she commits adultery by divorcing and marrying another.

Luke 16:18 states:

 Πᾶς ὁ ἀπολύων τὴν γυναῖκα αὐτοῦ καὶ γαμῶν ἑτέραν μοιχεύει, καὶ ὁ ἀπολελυμένην ἀπὸ ἀνδρὸς γαμῶν μοιχεύει.

Anyone who divorces/abandons his wife and marries another woman commits adultery, and the one who marries an abandoned/divorced woman commits adultery.

How exactly would a man be committing adultery by marrying a divorced woman if the one flesh union is broken by abandonment, especially an official abandonment in divorce? If she is no longer tied by that union to a husband, how is the third party committing adultery? The union should be broken, but Jesus says that it isn't.

Hence, this is why Paul states that if a woman is married to another man while her husband is living, she is an adulteress, and why she is free to marry if her husband dies.

Hence, the one flesh union that God has joined together, and commanded that no human is to separate, is in full force until one of the partners dies. This means that remarriage to another person is adultery if the previous spouse still lives, and that divorce/abandonment in no way breaks that union.