What constitutes a marriage in God's eyes?

I had a discussion recently with an individual concerning a couple who considered themselves married but had never obtained a license from the state or performed a ceremony before a civil or religious authority. They had been co-habitating for several years and even had children together. I stated that these individuals were living in sin because they had never been legally married. His response to me was, “Why do I judge them to be in sin just because they haven’t gotten a license from the state or had a wedding ceremony, Where does the Bible say they have to have these to be considered husband and wife or married?”

Well, being from the old school as I am, I just gave him the status quo response that I had always been taught and believed but as I pondered it myself after we parted I realized I didn’t have a good biblical background for my beliefs on the subject either. As I got into a study of marriage in the bible and researched resources on the subject, both biblical in nature and historical, I found my ground was even more shaky. The following is from the text “Ethics for a Brave New World” pg. 301.

BIBLICALLY, WHAT CONSTITUTES A MARRIAGE?

Though Paul teaches about Christian marriage (Ephesians 5), he focuses more on how husbands and wives should relate to one another than on what forms a marriage. Thus, this question seems best answered by appeal to the creation ordinances in Genesis 2. Genesis 2 shows that marriage is God’s idea (2:18). After God created the world and the first man, he decided man should not be alone. God created the animals, and Adam named them, but none was suitable as a helper for Adam (2:19–20). God then created Eve from Adam and brought her to him (2:21–22). Verse 23 records Adam’s words of recognition that she was the one suitable to be his helper. The passage ends (v. 24) by setting forth the elements that go into making a marriage in God’s eye.

Verse 24 states that because ( “for this reason”) a man recognizes a particular woman as suitable to be his mate, he leaves father and mother. The word for leave (’āzab) is a very strong word that means more than simple departure. It means “to forsake, leave destitute, or refuse.” The idea is not that a husband and wife no longer can have any relationship with their parents. Rather, they recognize that their relationship to one another must have priority over all other ties. It is in this sense that they forsake or leave their parents.

Marriage also involves a cleaving to one’s mate. The word for cleave (dābaq) means “to cling to, remain close, adhere, be glued firmly.” In this verse it means that once parents are forsaken, the man will not soon return to them. He will stay with his wife and direct his affection and attention to her. She will do the same to him. When the ideas of forsaking and clinging are taken together, it becomes clear that marriage amounts to each partner committing his/her life to the other. It is a pledge to emphasize one’s mate as paramount beyond all other relations (forsaking) and to remain faithful to (cling to) him/her.

The verse concludes by saying they will become one flesh. This speaks of union. The point is not that now there is only one person. Eve still had her own body and mind, as did Adam. Likewise, the phrase is not merely a reference to the sexual union of the partners. Surely, the phrase refers to the sex act, but the context demands that it mean more. We believe the phrase is a metaphor meant to signify the bonding or uniting of the two as a married couple. The sex act outwardly and physically points to the bond that has been created. Some argue that the phrase also signifies the creation of kinship or blood relation (cf. Gen 29:12–14; 37:27; Judg 9:2; 2 Sam 19:13).7

How is this union brought about? It comes into being as a result of two factors. The first is the commitment of life to one another, signified by the forsaking and cleaving of the partners to one another. The second is an act of God constituting or uniting them together. Jesus’command in Matt 19:6 not to put asunder those whom God has joined emphasizes the divine element in establishing the bond.

In my studies of the historical view of marriage I have also found evidence that before the middle ages most legal marriages were either arranged or of mutual consent whereby two individuals, male and female, agreed to a union of marriage and thus became man and wife. There was no secular or religious authority that had to give approval, and the only thing that might be considered equivalent to our contemporary wedding ceremony was the cultural celebrations that might accompany the joining of a man and woman as husband and wife and would sometimes last for days. It wasn’t until the Catholic church attempted to institute the rite of marriage under their authority that the question of legality and recognition before God and the State came into play. Even after this many of the reformers and protestant churches considered marriage to be a secular decision apart from church doctrine or sanction while others felt the clergy were the only ones who could establish a covenant of marriage before God and the Church.

So, I pose the question to those who are much more learned than myself, what constitutes a biblical marriage in our day and is civil license and/or secular/religious ceremony necessary for two people to consider themselves man and wife in covenant relationship with God?