Genesis 2:24 (ESV)

24 Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh.

You may wonder whether the words of this verse were spoken by Adam or whether the later human scribe wrote it down through the inspiration of the Holy Spirit. Whichever way you choose, it remains clear that the Lord gives a clear standard for marriage here. It is not just a description of what happens at and in marriage, but more importantly God’s norm and standard for all times. The Lord Jesus makes this very clear in Matthew 19, when the Jews ask if it is not possible to divorce your wife for all kinds of reasons, and Jesus responds with: Have you not read that he who created them from the beginning made them male and female, and said, Therefore, a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh? So they are no longer two but one flesh. What therefore God has joined together, let not man separate, (Matthew 19:4–6). We see very clearly here that the Lord Jesus calls the words of Genesis 2:24 God’s words (see also 1 Corinthians 6:16; Ephesians 5:31).

Marriage also implies distancing yourself from your family in a certain way. The husband will leave his father and mother and give and dedicate himself completely to his wife. For them, the relationship between the two in marriage has to be the most intimate union in their lives. These words also show that it is the will of God that marriage is a unique union between one man and one woman. In marriage people become one flesh and form a complete unity; there is no place for a third party in that relationship. Being one flesh is not just about the sexual relationship. It is about man and woman forming a unity of life in everything.