One flesh

A sign and expression of the inseparable union between husband and wife. This is not only physical but emotional, mental and spiritual. It is also used to describe the union between Jesus Christ and the church.

One flesh describes the inseparable union between husband and wife

Genesis 2:22–24 See also 1 Corinthians 6:16; Ephesians 5:28–29, Ephesians 5:31

And from the rib that the LORD God had taken from the man, He made a woman and brought her to him. And the man said: “This is now bone of my bones and flesh of my flesh; she shall be called ‘woman,’ for out of man she was taken.” For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh.

One flesh refers to sexual union which Scripture describes in various ways

To lie with

Genesis 4:1, Genesis 4:17, Genesis 4:25, Genesis 19:31–35, Genesis 29:21, Genesis 29:23, Genesis 29:30; 1 Samuel 1:19; 2 Samuel 11:11, 2 Samuel 12:24, 2 Samuel 16:21

To come together

Matthew 1:18; 1 Corinthians 7:5

To have union or unite with

1 Corinthians 6:15–16 See also Genesis 2:24; Matthew 1:25, Matthew 19:5 parallel Mark 10:7; Ephesians 5:31

Do you not know that your bodies are members of Christ? Shall I then take the members of Christ and unite them with a prostitute? Never! Or don’t you know that he who unites himself with a prostitute is one with her in body? For it is said, “The two will become one flesh.”

Natural relations

Romans 1:26–27

One flesh expresses an intimacy encouraged by God

Only within heterosexual marriage

Matthew 19:4–6 parallel Mark 10:6–9 See also Genesis 1:27, Genesis 2:24; Exodus 20:14 parallel Deuteronomy 5:18; Leviticus 20:10; Matthew 5:27–28; 1 Corinthians 5:9–11, 1 Corinthians 6:9, 1 Corinthians 7:4

Jesus answered, “Have you not read that from the beginning the Creator ‘made them male and female,’ and said, ‘For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh’? So they are no longer two, but one flesh. Therefore what God has joined together, let man not separate.”

Intimate relations between members of the same sex are unnatural and wrong

Leviticus 18:22 See also Romans 1:26–27; 1 Corinthians 6:9

You must not lie with a man as with a woman; that is an abomination.

One flesh describes the union between Jesus Christ and the church

Ephesians 5:31–32 See also Genesis 2:24; 1 Corinthians 6:16–17

“For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh.” This mystery is profound, but I am speaking about Christ and the church.