The instruction of the Lord God in Genesis 2:14-18 is of fundamental importance when it comes to evaluating the legitimacy of alternative ways of living together or forms of cohabitation. This paragraph provides more than merely a description of the special and unique way where in a distant past “a certain Adam” received a wife. The history described in Genesis 2 culminates in an institution from God for all men and women who will proceed from Adam: “Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh” (v. 24). This is not just a short summary of what had occurred in Adam’s private life, but an ordination from God that affects the time that will come, as becomes clear from the first part: it is about a man who will “leave his father and his mother.” And that does not apply to Adam; after all, he had no father or mother.

For all who confess the historic accuracy and fidelity of Genesis 2 and 3, it is clear that we cannot ignore Genesis 2:18-24 by labelling it as the response of a random culture to the problem of loneliness. Neither may it be labelled as an explanation of what was thought up in a particular moment about the mutual attraction of men and women. Genesis 2:18-24 is not the fruit of one culture or another. It contains the creation order that God has given prior to all cultures and which is normative for all societies, when he saw that it was not good that the man was alone (Gen. 2:18). What is set in Genesis 2:24 is not to be labelled a cultural phenomenon. It is the gift by which God from the outset and in a normative way (which is valid for all centuries and all cultures) provided in the general human need for a spouse (“a helper fit for him”).

Thus, the importance of Genesis 2:24 has been clarified for the topic at hand.

A few remarks, therefore, about the three parts of this central word of God.

1. “Therefore a man shall leave his father and his mother”: this portrays the strength and the closeness of the bond between a husband and his wife; that bond exceeds the relationship of parents and children: you will leave your parents for this. It is an entirely different bond than what you had as a child with your parents.

2. “And hold fast to his wife”: the verb for “holding fast” can have many shades of meaning, depending on the context in which it is used. Just like our word “relationship,” it indicates a relationship, the nature and intensity of which depends on the person with whom the relationship is maintained. When a daughter-in-law has a good relationship with her mother-in-law, we think of an entirely different relationship than that of a husband and his wife. And the word “relationship” gets again a whole different dimension when we speak about our personal relationship to God. The same holds true for “holding fast.” It can indicate intimate affection and loyalty (Ruth 1:14; 2 Sam. 20:2). It can also be a description of the fellowship with the Lord (1 Cor. 6:17). That a man holds fast to a woman, according to 1 Corinthians 6:16 (being ‘joined’ to a prostitute), refers to have sexual union with a woman. When this holding fast to a woman alludes to the inner affection of a man to his wife, this is expressly indicated: “the soul of Shechem was knit fast to Dinah” (Gen. 34:3); “to these strange women was Solomon joined” (1 Kings 11:2).

The sexual relationship can also in Scripture be indicated with the word ‘to know’ (see Matt. 1:25, “Joseph knew not Mary”). The fact that in Gen. 2:24 the word ‘holding fast” is used has to do with what is to follow. In the way of holding fast, husband and wife become one flesh, which means that they form a comprehensive and indissoluble unity.

By using the expression “holding fast,” “cleaving to,” the Lord indicates in Genesis 2 that sexual union is not something fleeting or incidental, something of a moment. It presupposes or creates a total and permanent relationship (a “being one flesh”). When someone holds fast to his wife, he is tied to her. Whether you experience this yourself and whether you are aware of it, or not!

This is also how the word is used in 1 Corinthians 6:16: “Or do you not know that he who is joined [holding fast] to a prostitute becomes one body with her? For, as it is written, ‘The two will become one flesh.’” The allusion to Genesis 2:24 in 1 Corinthians 6 is irrefutable.

Finally, note that Genesis 2:24 does not say that a man will hold fast to “a” wife or woman, but to “his” wife: the one who belongs to him!

3. “And they shall become one flesh”: often this is understood as an indication of sexual union, but that is not correct. This is clear from 1 Corinthians 6:15, 16.

In 1 Corinthians 6 the term “one flesh” shows the result of sexual intercourse. Someone who has sexual intercourse with a prostitute initiates a comprehensive union with her: he becomes one flesh with her, he makes the members of Christ into members of a prostitute! With Paul the expression “one flesh” indicates therefore a total unity of body and soul, a unity that in our terminology is used in a similar way to indicate: husband and wife are one.

In Ephesians 5 Paul uses the expression “becoming one flesh” from Gen. 2:24 in the same manner. In verse 28 he writes, with an appeal to the fact that husband and wife are one flesh, that the man who loves his wife loves himself.

And from what the Lord Jesus says in Matt. 19 it also appears that “being one flesh” is not only about an all-inclusive unity, but also an indissoluble unity. Being “one flesh” is a being joined together by God, something that cannot be undone by any person: “So they are no longer two but one flesh. What therefore God has joined together, let not man separate” (Matt. 19:6).

When the Lord Jesus and his apostle Paul quote Gen. 2:24, they do so in connection with the Greek translation of Genesis 2. They do not write, “They shall become one flesh,” but “These two shall become one flesh” (Matt. 19:5; 1 Cor. 6:16; Eph. 5:31). With this expression nothing is added to Gen. 2:24, but it identifies what God meant with this rule of paradise: a total and lifelong bond between two people; more precisely, between one husband and one wife!