Is it adultery to marry a guy who has a child but was never married?



I am talking to a guy who has never been married but is a single father, having a child from a previous relationship. Would it be considered the sin of adultery if I were to ever marry him? I ask because the Scriptures talk about two joining together and becoming "one flesh". I am guessing "one flesh" means a child. Then it goes on to say what God brought together let man not separate (Referencing Matthew 19:6). However, this man and the mother of his child never married. I once heard though that God considers consummation of marriage to be when two people are intimate. Would it be a sin to ever marry this person because they had a child with someone else? Does God view this man as being married to the person he had a child with, even though they were never married by law and are also are no longer together?


"Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh" (Genesis 2:24).

"Joined" is from the Hebrew dabaq, which means to be joined together. So the steps to form a new family are leave parents, join in marriage (Matthew 19:6), and then become one, which is an on going process.

Joseph and Mary prove that sex does not create a marriage: "Then Joseph, being aroused from sleep, did as the angel of the Lord commanded him and took to him his wife, and did not know her till she had brought forth her firstborn Son" (Matthew 1:24-25). Joseph and Mary were married and sex did not come until after Jesus was born. This is absolute proof that marriage takes place before sex and does not require sex to seal it.

"Do you not know that your bodies are members of Christ? Shall I then take the members of Christ and make them members of a harlot? Certainly not! Or do you not know that he who is joined to a harlot is one body with her? For "the two," He says, "shall become one flesh"" (I Corinthians 6:15-16).

Who did the joining? In I Corinthians 6:16, it is man who is coupling with a prostitute. They become one body for a moment in time, but there is no marriage because God didn't join the two. If sex made the marriage, then the first person you had sex with would be your spouse. But that has never been the case.

"If a man entices a virgin who is not betrothed, and lies with her, he shall surely pay the bride-price for her to be his wife. If her father utterly refuses to give her to him, he shall pay money according to the bride-price of virgins" (Exodus 22:16-17).

Notice the order: a man and woman have sex, he pays the dowry, and if her father agrees, they get married. The act of sex did not create a marriage. The penalty was to force marriage, but the woman's father could say "no" to the marriage.

Therefore, a man having sex with a prostitute doesn't make him married to the prostitute, but it does make him "one body" with her. The conclusion is that "one body" and marriage are not the same thing.

Let's make an important point: in the Bible "law" and "covenant" are equivalent terms.

  • "They did not keep the covenant of God; they refused to walk in His law" (Psalms 78:10).
  • "The earth is also defiled under its inhabitants, because they have transgressed the laws, changed the ordinance, broken the everlasting covenant" (Isaiah 24:5).
  • "But this is the covenant that I will make with the house of Israel after those days, says the LORD: I will put My law in their minds, and write it on their hearts; and I will be their God, and they shall be My people" (Jeremiah 31:33).
  • "Set the trumpet to your mouth! He shall come like an eagle against the house of the LORD, because they have transgressed My covenant and rebelled against My law" (Hosea 8:1).
  • "But you have departed from the way; you have caused many to stumble at the law. You have corrupted the covenant of Levi," says the LORD of hosts" (Malachi 2:8).

Understanding this, Paul's statement is clearer: "For the married woman is bound by law to her husband while he is living; but if her husband dies, she is released from the law concerning the husband" (Romans 7:2). The "law" mentioned here is not the Old Testament but the covenant she made with her husband. Paul's point is that you could not be under two sets of laws, or two covenants, at the same time. For a woman to marry again, she had to be freed from the law, or covenant, that bound her to her husband. Notice that the binding and releasing had nothing to do with the act of sex, but by the law (the covenant). That is why this situation becomes a parallel for the Jewish people. They were freed from their first covenant by the death of Christ, allowing them to be bound by the second covenant.

The same concept is repeated: "A wife is bound by law as long as her husband lives; but if her husband dies, she is at liberty to be married to whom she wishes, only in the Lord" (I Corinthians 7:39). To say she is bound by law is exactly the same idea expressed in Malachi 2:14 when it says "Yet she is your companion and your wife by covenant."

This man committed the sin of fornication. A consequence of his sin is that he now has a child. This does not make him married to the woman he had sex with. You would not be committing adultery if you decided to marry him.