Note 3 at Mt 19:5: Who said this? It is evident from the context here that God spoke the following phrase. However, this is a quotation from Ge 2:24, which was spoken by Adam. This illustrates how God can inspire and speak through people. Adam, who had no father or mother, was speaking prophetically, thus making marriage a sacred and not merely a civil institution.

Note 4 at Mt 19:5: What does it mean for a man and a woman to become "one flesh"? The act of sexual intercourse between a man and a woman produces this one flesh relationship, as can be seen by 1Co 6:16: "What? know ye not that he which is joined to an harlot is one body? for two, saith he, shall be one flesh." This means that whether or not the man and woman ever cleave to each other in marriage, this physical act binds them together as one flesh.

This is the reason that sexual relationships outside of marriage (whether extramarital or premarital) are so damaging. Whether or not people get caught or pregnant or ever hurt anyone else with their sins, they are doing a lot of damage to themselves. 1Co 6:18 says, "Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body."

A relationship takes place through the sexual act that makes a person one with another person. There is no such thing as just a "night on the town" or a "one-night stand," and that's all there is to it. Alcoholism, child abuse, hatred, and a thousand other things that are certainly wrong are not grounds for divorce, but fornication is. That shows that something very powerful takes place in the physical act and explains why Satan has exploited this area so much.

Becoming one flesh with someone (sexual intercourse) is not marriage. Marriage includes, but is even beyond, becoming one flesh. This can be seen very clearly in Joh 4:17-18. Jesus said the woman He was speaking to at Jacob's well had previously had five husbands, and the man she was living with at that time was not her husband. It is certain that this woman was having sexual relations with this man she was living with, but that didn't make him her husband.

Therefore, marriage involves more than sexual relations. It is a covenant, a commitment, between the two partners that would correspond to the cleaving to each other that Jesus spoke of here. Once this covenant is entered into, which is customarily done through the wedding ceremony, and the physical relationship is shared, a couple is married in the sight of God.