What does “two becoming one flesh” refer to?

Question

In the bible when it refers to the two becoming one flesh, does it mean:

• The physical act of sex creates a position where both body's are connected

or

• The flesh from man and flesh from woman (DNA) unite to form one flesh (child composed of both father and mother)?

or

• something else completely?

Answer 1

While I can see a certain level of applicability to the first two points you mention, I think the most meaningful and relevant answer is something else entirely.

If you look at the at-one-ment of Jesus Christ, in terms of what Jesus taught in the intercessory prayer (John 17:20-23), you can see that he is calling for union to take place between those who are believers.

When you look at the structure of what Jesus Christ organized, you can see a system of ordinances that have covenants coupled with them. Just as a man and a woman enter into a marriage covenant and become "one flesh" so too do believers who join together in a body form a body of one flesh.

So, as I see it, the concept of "one flesh" means that multiple individuals join together in covenant and are organized into some kind of a greater collective identity that can be looked at as its own distinct individual entity.

The marriage between a man and a woman is simply one example of it on one level, but the underlying concept is applicable on a more universal scope at varying levels.

Paul teaches another example of this where in Ephesians 5:30 he says that everyone who joined the Church of Christ is a member of the body of Christ, of His flesh and of His bones.

And, in actuality, as members of the church they are members of the body of the Bride of Christ. But, since Christ and His Bride are married and "one flesh" then Christ can say of the church members that they are "bone of my bone and flesh of my flesh" just as Adam said to Eve. (Genesis 2:23)

Answer 2

The saying the Bible "The two become one flesh" is almost always in reference to marriage and all that it means.

The saying is found in Genesis 2:24, when God instituted marriage, Mark 10:8, when Jesus was commenting on the permanent nature of marriage, and Ephesians 5:31, when Paul uses marriage as a symbol of the relationship between Christ and the church.

The full extent of the verses in Genesis is:

23 The man said,
“This is now bone of my bones
and flesh of my flesh;
she shall be called ‘woman,’
for she was taken out of man.”
24 That is why a man leaves his father and mother and is united to his wife, and they become one flesh.

In Ephesians, when Paul quotes Genesis he says "This mystery is profound," then moves back on topic about Christ and the church. This really only tells us that it is likely we cannot really understand the connection between a man and a woman in marriage.

The only truly reveling verse is Mark 10:8. Jesus is directly questioned if divorce is acceptable. He responds by quoting Genesis then says "Therefore what God has joined together, let no one separate." This is simply that marriage is permanent. You cannot leave your marriage because God joined the two together.

There is a similar question here that should shed more light on the topic.

Summary in short: "Two become one flesh" is about marriage and the mysteries within that institution.

Answer 3

St. Paul assumes the quote to be talking about the intercourse in 1 Kor 6, 16

16 Or do you not know that he who is joined to a prostitute becomes one body with her? For, as it is written, "The two will become one flesh"