Feedback archive Feedback 2011

Cain’s wife and brother-sister intermarriage

iStockphoto one man one woman

Nicholas J. from the USA disputes our solution for Mrs Cain because of the Mosaic Law against brother-sister intermarriage, and proposes an alternative. Dr Jonathan Sarfati of CMI–US (formerly CMI–Australia) defends our solution, explains the reason for the Jewish law, and why it didn’t apply to Cain.

To whomever is reading this from creation.com. First let me say that I have found your website very helpful in many ways. My wish in sending you this message is to strengthen your undertaking and to help those who visit your website who are searching for good answers.

I have read much of what creation.com presents on the topic of Cain’s wife, and I have to say that I am in disagreement with what I find. I commend the authors who have written the material on your website for diligently working toward uniting the clear message of scripture with an understanding of all creation and history. However, I am in disagreement with the answer presented here, and I hope you will allow me to offer another view that has the same intentions of uniting Scripture with all of life. I present this view in the following paragraphs:

Question: Where did Cain’s wife come from?
Answer: It is very likely that God formed a wife for Cain from his own body in the same way that God formed a wife for Adam. It is also possible that God could have formed her from the ground.

Many will say that God could not have created other people outside of Adam and Eve because the rest of the Bible is clear that we are all in Adam. For instance, the Bible is clear that sin entered the world through one man (Romans 5:12). However, it is a non sequitur to conclude from this verse that all people must be physical descendents of Adam. The Bible says that all Christians are in Christ, but are all Christians physical descendants of Jesus? Of course not, for then no Christians would exist. Just as Christ is made a federal head for those who believe in Him, so is Adam made the federal head of all mankind by being the first man to be created.

For those who are not persuaded by the argument in the last paragraph, I point out that if Cain’s wife were created from his own body, formed in his own image and likeness, the woman would still be a physical descendant of Adam. For Cain’s wife to come from his own body seems to fit best with the Biblical story as a whole.

Many have argued that Cain simply married one of his sisters. I believe that this answer is an impossibility. Those who hold to this answer concede that God gave laws forbidding sexual acts between close relatives (Leviticus 18; Deuteronomy 27), but they argue that God did not give these laws until the time of Moses, and so early humans (including Cain) were excluded from these laws. However, this argument fails for the reason that God’s moral law is unchanging. If the moral law of God has no meaning until it is given, then Cain also did no wrong in murdering his brother Abel, and yet God holds him responsible for it. For the ‘sister argument’ (if I may call it that) to work, incest must be considered ceremonial or civil law, but it is clear from the context of Leviticus 18 and Deuteronomy 27 that we are to consider incest to be moral law. If it is indeed moral law, then it is impossible for God to have commanded mankind to multiply and fill the earth by means of incest, for God would have been commanding disobedience unto Himself.

Furthermore, we must consider the reason that God gives for forbidding incest, or as the Bible expresses it, uncovering the nakedness of a relative: ‘for their nakedness is your own’ (Lev. 18:10). Those who argue that Cain married one of his sisters claim that the law against incest was only given at a later time in order to protect people from biological defects, but that is not the reason that God gives for His commandment.

The argument is often made that incest could not be inherently against God’s moral law if He blessed the marriage of Abraham and Sarah, who were half-siblings. This argument can be refuted quite simply. Does God only bless people and their actions if they are sinless? I should hope not. If that were true, no one would be saved. The refutation of this argument is the Gospel.

Dear Mr J.

Thank you for writing to us with your thoughts, and for your kind comments about our site.

You might not be surprised to find that we don’t agree. I addressed a similar argument to yours (although yours was expressed much better) at Cain’s wife explanation ‘gross and disgusting’?

A serious problem with your view is that there is simply not the slightest hint in the Bible that Cain’s wife was miraculously created. Only Adam and Eve were created without ancestors, and after that, only Jesus was born without a human father. All other humans who have ever lived were the result of generation, not creation, which was finished after Day 6 (Genesis 2:1–3).1 Thus all humans are born “in Adam”, while we are born again in Christ, clearly stated to be spiritual, as John 1:12–13 says:

Yet to all who did receive him, to those who believed in his name, he gave the right to become children of God—children born not of natural descent, nor of human decision or a husband’s will, but born of God.
It would be better to say that God’s moral standard does not change, reflecting His unchanging nature. But because the Bible records Heilsgeschichte (salvation history), the individual commands change to conform to His unchanging standard as the Messianic Program is being worked out through history.

Also, your argument on its own might be defeated by saying, “So what? Cain was a murderer, so why should he care about an alleged divine law against brother-sister intermarriage?” But I won’t resort to that as a defense of the truth of the whole Bible, because there is a similar problem with Adam’s unfortunately lesser-known son Seth, our ancestor: where did he get his wife? Was she specially generated as well? Or did he marry one of Cain’s daughters, his own niece, although Cain had been exiled by then? And for that matter, where did Cain’s son Enoch get his wife, given that Cain was exiled? Brother-sister marriage is inescapable, unless we resort to more such deus ex machina explanations of special creations of more women.

Another problem is this artificial separation of moral and ceremonial laws. Surely every law God gives is a ‘moral law’, in that it would be immoral to disobey. The Mosaic Law of 613 commandments is a unity, which is why James told us that breaking one commandment was breaking the whole Law (James 2:10). And were we to categorize the law that Adam broke, it would come under ‘ceremonial’ since it was a prohibited food law.

It would be better to say that God’s moral standard does not change, reflecting His unchanging nature (see also What is ‘good’? (Answering the Euthyphro Dilemma)). But because the Bible records Heilsgeschichte (salvation history), the individual commands change to conform to His unchanging standard as the Messianic Program is being worked out through history. For example, God’s eternal plan was that Christ’s death and resurrection would enable the salvation of those written in the Book of Life from the foundation of the world (see The Incarnation: Why did God become Man?). Thus during the Mosaic period, it was moral to sacrifice animals to cover sin; after Christ’s death and Resurrection, it is now immoral to do so because that would deny the perfection of Christ’s work for us, taking away sin (Hebrews 10).

Similarly, God told Adam and Eve to eat plants (except for one), after the Flood He permitted Noah to eat any animal as well, but during the Mosaic Law, God forbade the eating of certain types of animal. Under the Law of Christ, we may now eat the animals that were forbidden under Moses. At any of these times, it would have been immoral to eat anything God had forbidden.

God told Adam and Eve to eat plants (except for one), after the Flood He permitted Noah to eat any animal as well, but during the Mosaic Law, God forbade the eating of certain types of animal. Under the Law of Christ, we may now eat the animals that were forbidden under Moses. At any of these times, it would have been immoral to eat anything God had forbidden.

Like you with the incest law, I would de-emphasize the health benefits of the Mosaic food laws, and look to the symbolism: at this stage of the outworking of the Messianic Program, the Messianic People were to be separate from the surrounding nations. Thus the laws repeatedly had ritual separation: no clothes made from a mixture of fabrics; no eating lobster, because the legs on a sea creature violated the ritual boundary between sea and land.

But since the coming of Christ, the barrier between Jew and Gentile has been broken down (Ephesians 2:14). Now both Jews and Gentiles can become one in Christ Jesus (Galatians 3:28, Col. 3:11). Thus there is no longer any place for those separation laws, which are now rendered obsolete (Hebrews 8:13). See “Is eating shellfish still an abomination?” and “A brief history of the Jews”.

When it comes to the law at hand, there is simply no evidence from practice or logical deduction from Scripture that brother-sister intermarriage was God’s command until it was given. The command in Leviticus 18:10 just says,

“Do not have sexual relations with the daughter of your father’s wife, born to your father; she is your sister.”

A reason might be that by this stage of the Messianic program, the family was regarded as an extension of one’s own flesh (cf. Genesis 2:24), and violating “any flesh of his flesh” was then a sin (Leviticus 18:6). But as the scholarly 19th-century commentary by Jewish Christian scholars Keil and Delitzsch point out:

“There Cain knew his wife. The text assumes it as self-evident that she accompanied him in his exile; also, that she was a daughter of Adam, and consequently a sister of Cain. The marriage of brothers and sisters was inevitable in the case of the children of the first men, if the human race was actually to descend from a single pair, and may therefore be justified in the face of the Mosaic prohibition of such marriages, on the ground that the sons and daughters of Adam represented not merely the family but the genus, and that it was not till after the rise of several families that the bands of fraternal and conjugal love became distinct from one another, and assumed fixed and mutually exclusive forms, the violation of which is sin.”

But this is still a reflection of God’s unchanging standard, which was the protection of humanity. Originally, any man could marry any woman. But by the time of Moses, we can see from the decreased life spans that many harmful mutations had accumulated (see Living for 900 years). So God maintained His standard by now forbidding close intermarriage, to minimize the chance of harmful mutations being expressed in the offspring—a problem that didn’t exist with the children of the genetically perfect first couple.

Our Creation Answers Book provides the following illustration in the Cain’s Wife chapter:

“This sometimes causes people to ask if that makes God inconsistent—isn’t He changing His standards? Imagine a shepherd looking after his flock on an open meadow. There are no wild animals around, and the only danger to the sheep is at one end of the meadow, where there are some cliffs from which they could fall down. So the shepherd builds a fence, but only around the cliffs. That fence represents a law, a ‘Thou shalt not’. There is no need to fence the rest of the meadow.

“Some time later, wolves move into the district. Now there is a new danger to the sheep; if they stray beyond the sight of the shepherd, they risk being killed and eaten. So a new set of rules is called for, a new ‘Thou shalt not’, and the shepherd now puts a fence around the entire meadow.

“The shepherd’s standards have not changed; his loving care for the flock is the same as always. But times have changed, and a new law is called for in order to express that loving care.

“In the same way, having permitted intermarriage between close relatives in order to commence humanity from one man (and one woman who also came from that one man), a point was reached where God clearly chose to institute a new law which was, like in the case of the sheep, a benefit to them, for their own protection.”

Finally, why was Cain guilty of murder although the Mosaic Commandment had not been given (and why were the Sodomites guilty of sexual sin before the Mosaic commands against homosexual behaviour)? Answer: before Moses, God had written the moral law on people’s hearts. This is not directly stated in Genesis, but is logically deducible from Romans 2:14–15:

(Indeed, when Gentiles, who do not have the law, do by nature things required by the law, they are a law for themselves, even though they do not have the law. They show that the requirements of the law are written on their hearts, their consciences also bearing witness, and their thoughts sometimes accusing them and at other times even defending them.)

God’s writing the Law on the hearts of the early biblical characters makes far more biblical sense than a special creation of their wives.

I hope this explains our position more fully.


Jonathan Sarfati

Published: 14 May 2011


  1. I am aware of claims made about Melchizedek, because of Hebrews 7:3:
    Without father or mother, without genealogy, without beginning of days or end of life, like the Son of God he remains a priest forever.
    However, the description “Without father or mother, without genealogy” refers to the fact that these are not recorded in Scripture, and were not necessary for his type of priesthood, in contrast to the Levitical (cf. v. 6). He was made like the son of God, not the Son of God himself; the likeness was in terms of the sort of priesthood, where he was a type of Christ. He could not have been the pre-incarnate Christ, because a priest must be human, while the Second Person of the Trinity took on humanity only at the Incarnation (see The Incarnation: Why did God become Man?). Rather, the name is a typical Jebusite name, like Adonizedek, making it likely that he was an exceptionally godly priest-king but still a normal man. Return to text.

Helpful Resources