Leaving Behind Father & Mother
God created the "husband" to reflect His Son's role toward mankind, especially toward His people.
The husband is the foundation of marriage; everything starts with him. This reflects that it was God Who called us through His Son, therefore:
19We love him, because he first loved us. 1 John 4:19
For, just as the husband calls the wife, so has the Lord Jesus called us—not the reverse:
16You didn’t choose me, but I chose you, and appointed you, that you should go and bear fruit, and that your fruit should remain; that whatever you will ask of the Father in my name, he may give it to you. John 15:16
After seeing us, the Lord Jesus left His home (Heaven), and the company of His Father (Yahweh), to become one with us (the Assembly), who is the Bride.
31“For this cause a man will leave his father and mother, and will be joined to his wife. The two will become one flesh.” 32This mystery is great, but I speak concerning Christ and of the assembly. Ephesians 5:31-32
As Paul says, this mystery is great—the idea of a man leaving his father and mother in order to be joined to his wife; but he refers not to fleshly man and woman, but Christ and the Assembly. So we see the primary truth being revealed by God through marriage is His relationship to us in His Son; however, we should not neglect the type of earthly marriage, which has its benefits and blessings for us (Ephesians 5:33).
What does it mean "to leave" in this context? The word here (καταλειψει) is made of two basic Greek roots meaning "according to, down from, along" and "to leave behind, to lag, to forsake." It is similar to the word used in another study ("Loving the Present Age"), which is translated "forsake" in that context. It really does mean to leave behind as when called away by another.
The husband sees the woman, and desiring her, leaves behind his father and mother (Genesis 29:10-18). The very ones who raised him from birth, who brought him into this world, he must leave behind—and he does this in order to be joined to another (the wife). This new union with the wife can even help to soothe the pains of the past relating to the husband's parents.
67Isaac brought her into his mother Sarah’s tent, and took Rebekah, and she became his wife. He loved her. Isaac was comforted after his mother’s death. Genesis 24:67
In turn, they together will continue the cycle, as they bear children who once grown up will leave them behind in order to be joined to others, and so on.
So the emphasis on the leaving lays upon the husband. Although it is obvious the wife must leave behind her family as well, it is the leaving of the husband that is stressed. He then takes the woman from her old life in order to create a new one with him. Whereas he takes her, she is taken by him, just as it is with God and His people (Numbers 18:6) (Deuteronomy 4:20) (Deuteronomy 7:6).
2For I am jealous over you with a godly jealousy. For I married you to one husband, that I might present you as a pure virgin to Christ. 2 Corinthians 11:2
Once the man leaves to be married to a wife, he no longer answers to his parents. He no longer is under their authority, but has begun his own home with the wife. Therefore, to allow his (or her) parents to interfere with their new life would be to disregard the revelation of God concerning marriage—it is to be a leaving behind of father and mother in order to be joined to another.
Truly, a new life has begun when the man leaves home to be wed to his wife.
Discerning Yahweh
We find that the Son of Yahweh truly loves us. He left behind His heavenly abode in order to be joined to us.
Think of how great His joy was, in constantly being in the presence of His Father, yet He loved us so much to draw Him out of heaven and to be born the Son of Man, that He might be wed to us.
In seeing the sacrifice He made in order to marry us, those who believe in Him, so we understand that He shares the nature of His Father, Yahweh—for God is Love.