Also Available in:
Click to view PDF

Who was Cain’s wife?

The Creation Answers Book (8th ed. 2019), Chapter 8


Creation Magazine Volume 46 Issue 2 Cover

Chapter 1Does God exist?

Chapter 2Six days? Really?

Chapter 3What about gap theories?

Chapter 4What about carbon dating?

Chapter 5How can we see distant stars in a young universe?

Chapter 6How did bad things come about?

Chapter 7What about similarities and other such arguments for evolution?

Chapter 8Who was Cain’s wife?

Chapter 9Were the ‘sons of God’ and/or the nephilim extraterrestrials?

Chapter 10Was the Flood global?

Chapter 11What about continental drift?

Chapter 12Noah’s Flood-what about all that water?

Chapter 13How did all the animals fit on Noah’s Ark?

Chapter 14How did freshwater and saltwater fish survive the Flood?

Chapter 15Where are all the human fossils?

Chapter 16What about ice ages?

Chapter 17How did animals get to Australia?

Chapter 18How did all the different ‘races’ arise (from Noah’s family)?

Chapter 19What about dinosaurs?

Chapter 20What should I do?

  • It’s now not lawful to marry your sister. So if Adam and Eve were the only two people God created, how could their son Cain find a wife?
  • How is this important to the Gospel?
  • What about the land of Nod?

Illustration by Tim Newcombe14710-cains-wife

‘Who was Cain’s wife?’ (in one form or another) is one of the most commonly asked questions, by believers and unbelievers alike.

Sometimes the person asking is genuinely seeking an answer, puzzled about the issue. At other times, the question is asked triumphantly, even smugly, as if to imply, ‘There can’t be an answer; it’s an impossible conundrum.’ And indeed, on the surface it looks like an insoluble ‘catch-22’ for the Bible-believer.

Three of Adam and Eve’s children are mentioned by name: Cain, Abel, and Seth. Cain kills Abel, and after that it mentions his wife. So where did she come from?

The Bible makes it plain that Adam and Eve were the only two people that God created in the beginning. Adam is called ‘the first man’ (1 Corinthians 15:45, 47), and Eve “the mother of all living” (Genesis 3:20).

To start a whole population off from only one couple means that in the early generations there would have to be all sorts of close intermarriage, and at least one instance of brother-sister intermarriage. If Cain himself did not marry his sister, but rather a niece, that means that at least one of Cain’s brothers must have married a sister, anyway.

However, here it seems that the Bible-believer is faced with a dilemma.

1. The (apparent) biological problem

In the rare instances of known brother-sister intermarriage, there is a very strong likelihood that there will be various defects and deformities in the offspring. This is a biological fact.

2. The (apparent) moral problem

Doesn’t God Himself prohibit brother-sister intermarriage? Yes, God’s Law, handed to the Israelites via Moses, makes it clear that close relatives may not intermarry. In fact, even marrying a half-sister was strictly forbidden in the laws detailed in Leviticus. The law codes of many countries reflect similar prohibitions.

The ‘other people’ escape hatch—does it work?

Some have tried to solve the problem by claiming that there must have been other people present at the time, i.e. that God originally created more than the one man and woman. However, this causes even bigger problems. First, as already alluded to, it undermines the plain reading of several different parts of the Bible that make it clear that Adam and Eve were the first man and woman, respectively. And most Bible skeptics are quick to point this out.

Also, Paul makes it clear in the New Testament that all people alive on Earth today are Adam’s descendants. He says, “From one man he [God] made every nation of men” (Acts 17:26). And Genesis 2:20 (where Adam names the animals) indicates that there was no other member of Adam’s kind present—no living creature on Earth at that time was suitable to be a mate for him.

More importantly, the suggestion that some humans did not descend from Adam and Eve undermines the logic of the Gospel presented in the New Testament. It is clear that a precondition for salvation is to be a physical descendant of Adam. Jesus Christ is called “the last Adam” (1 Corinthians 15:45). The Lord Jesus is stated to be our ‘kinsman-redeemer’ (the definite sense of the word used in Isaiah 59:20, “the Redeemer shall come to Zion”—this uses the same Hebrew word גּוֹאֵ֔ל (gôēl) as used to describe Boaz in relation to Naomi (Ruth 4:14)). This is so because He, God the Son, took on human nature as well as being divine, becoming the perfect God-man.

This was God’s solution to the problem of sin. After the disobedience of the first Adam brought in the Curse of death and bloodshed, the obedient last Adam shed His blood in death, overcoming death through His Resurrection. That is the whole point of Paul’s message in 1 Corinthians 15:21–22. As a result, those who receive, by faith, His gracious gift of forgiveness of sin are no longer subject to eternal condemnation, but have everlasting life.

So this means that for anyone to be saved, they must first be a physical descendant of Adam, or else the Redeemer could not be their ‘kinsman’.1 The book of Hebrews also explains how Jesus took upon Himself the nature of a man to save mankind, but not angels (Hebrews 2:11–18). We can be saved because the last Adam entered our human line—descended from the first Adam, as we all are. The repeated Adam–Christ linkage is clear. That may be why it was important for Eve herself, in order to qualify for salvation, to also be a physical descendant of Adam (“bone of my bones, flesh of my flesh”—woman made from man’s rib). If she had been created in a totally separate fashion—from raw materials, as Adam was—she would not have been a ‘descendant’ of the ‘first Adam’.

The same principle also explains why long-age beliefs are so injurious to people such as the Australian Aborigines. If they have really been in Australia for 40,000 years (according to carbon-14 dating, which is so uncritically accepted by so many—see Chapter 4), then how could they come from Adam, who lived about 6,000 years ago according to the Bible. This means they could not be related to Christ, so how can they be saved?

This ‘Gospel link’ is an important reason why this issue of Cain’s wife is so important to the Christian. The other main reason is that it is such a widely used point with which the reliability (and hence the authority) of the Bible is challenged and attacked.

Proposing that there were people around that could serve as spouses for Cain and his siblings opens the door for all manner of bizarre (even racist) ideas. It suggests that some people were/are ‘human’ enough to intermarry with others, but not ‘human’ enough to be saved by the Lord Jesus.2

All in all, it is biblically unacceptable to try to escape the ‘Cain’s wife’ conundrum by proposing this idea of ‘other created people’.

So we are back to the seeming dilemma. The Bible says Cain had a wife—how could that be? Perhaps it’s no wonder that skeptics trying to find reasons not to believe the Bible, and/or to dissuade others from doing so, have attacked this part of Genesis repeatedly. They are confident that there is no rational solution. One of the most well known was the agnostic antitheist Clarence Darrow, lawyer for the evolution side at the famous Scopes trial. He cross-examined the anti-evolutionist William Jennings Bryan on the witness stand at that trial. Darrow successfully humiliated his opponent when Bryan was unable to give an answer concerning Cain’s wife.3 And thanks to biased reporting of the event from anti-Christian H.L. Mencken, this ignorance was imputed to all who believed in the truth of Genesis.

In the popular movie Contact (based on a book by the atheist evolutionist Carl Sagan), the atheist heroine (played by Jodie Foster) says that she lost her childhood faith because her pastor was unable to answer when asked, ‘Where did Cain get his wife?’ The message that this movie preached to millions was clear: ‘There is no answer; Christianity is not rationally defensible.’

If Hollywood thought that Christians were able to easily answer this question, it would be very unlikely to put dialogue like this into a major movie, for fear of a major public loss of face.

The sad thing is that many, perhaps the majority of, believers down through the years, have not been able to answer this. They often avoid the question, in fact, saying that it is ‘unimportant’. But the message that onlookers get from such evasiveness is clear: ‘They don’t want to answer because they have no answer.’ Another reason for this inability to answer may well be that we are not used to thinking within a consistent biblical worldview; one in which everything fits together. Mostly, we become used to thinking in terms of ‘spiritual’ things being quite separate from the facts, such as science, history, and so on.

However, the Bible’s salvation message is firmly rooted in history. If it is wrong about the early history of this world, how can it be trusted with our spiritual destiny at stake? Jesus said in John 3:12: “If I have told you of earthly things and you don’t believe, how will you believe when I tell you of heavenly things?”Jesus always spoke of the characters in Genesis as real and literal people, and the events as straightforward history.4

A supporter of Creation Ministries told us that an acquaintance of his, aged in his 90s, was dying. He had for years resisted all witnessing, including that of our supporter, his friend. When that supporter pleaded with him to accept Christ before he passed into eternity and it was too late, the dying elderly man stated that he could not, because he could not believe the Bible. And the reason was that no Christian he asked could answer his question on Cain’s wife, which is why he had years ago given up. He had stopped even asking the question.

A few years ago, at a country fair5 in Goondiwindi, Australia, a CMI representative was displaying a large model of Noah’s Ark. As folk milled around, fascinated by the huge size of the vessel relative to the model animals, a brash woman approached, pushing her way through the crowd. With a smug expression, she said, in a broad rural Queensland accent, “I betcha can’t answer my question. I’ve been asking Christians the same question for years, folks, and no-one can give me an answer, even though I tell ’em I’ll give ’em a thousand dollars if they can answer it. So there you are”, she said gloatingly to the Ark displayer in front of everyone, “You can have a thousand dollars if you can answer my question.”

“What is your question, then?” said the man representing our ministry. Hands on hips, the woman said, with a triumphant smirk, “All right, then … where did Cain get his wife, eh?” When she received the answer (which we will see is rational, coherent, and both biblically and scientifically sound) she seemed shell-shocked. She walked around as if in a daze, saying repeatedly to herself, “They answered my question … They answered my question … .” (She may have been even more shocked when told she could keep her thousand dollars!)

The point of all this lead-up to giving the answer is to show that the failure to come to grips with this challenge has been widespread, and has serious consequences. Believers are commanded to be ready to give an answer to defend our faith (1 Peter 3:15).6

So, what is the answer?

First, the biological issue

It is not true to say that marrying a relative will inevitably cause deformities—we all marry relatives. We are all related to varying degrees, because we have all descended from the same original parents. (If your husband or wife is not a relative, you have a problem, as it would mean you’re not married to a human being!)

The biological problems (and the moral and legal prohibitions) that we are considering here have to do with marrying close relatives. So let’s look at why there are defects and deformities in the offspring of close intermarriages. Where do the defects come from?

To understand this, we need some basic facts of genetics. The hereditary information that is passed on from generation to generation is encoded on stretches of DNA that include the well-known ‘genes’.7 As that information is copied repeatedly, it is copied chemical letter by letter. During this, copying mistakes can arise. These are called mutations. Mutations are responsible for thousands of inherited diseases, like cystic fibrosis, hemophilia, progeria, sickle cell anemia and phenylketonuria. These are passed on through the generations, because once such a mistake or ‘copying error’ has arisen, that error is copied, too. (When making a copy of a computer program or word processing file that has a defect, one ends up copying the defect, too.)

If there are successive generations of copying, as in biological heredity, then that mistake is not only passed on, but sooner or later another mistake will arise, which is then added to the original mistake. And so on. If we had a population whose genetic information contained only one mistake, then sooner or later there will be a population containing two mistakes. And then three, and so on. Future defects will tend to be added to the existing ones. This problem of the increasing genetic (or mutational) burden or load is a well-known phenomenon.8

In other words, over time such mistakes accumulate. The number of these defects in the population tends to progressively and relentlessly increase. This is why each one of us carries many hundreds of genetic mistakes. They have been inherited from the accumulation of copying mistakes occurring as our ancestors had children.


= Normal gene
= Defective gene


This person has normal instructions for this characteristic inherited from both parents—he/she will not express any defect for this particular characteristic.


This person has a defective gene from one parent. However, the gene from the other parent carries the normal instructions for this characteristic, functioning like a ‘backup copy’. So this person will normally not show any defect for this characteristic.9 This person is a ‘carrier’ for the defect, without showing it. We all ‘carry’ many such mistakes, which we don’t show.


This person has inherited the defective gene from both parents. He/she does not now have any normal instructions for this characteristic, so the characteristic itself will be defective/deformed.10 We are all related, but the closer your relatedness with the person you marry, the greater the chance you have some of the same mistakes. This makes it more probable that a child of such a marriage will inherit the same mistake (mutation) from both parents, thus giving rise to the expression of overt deformities and defects.

For a gene involved in a particular trait (the ability to make insulin, for example11) you inherit one gene from your mother and one from your father. So it is as if you have a ‘backup copy’ of normal instructions if one should be defective. Say you have inherited a defective copy of a particular gene, giving, for example, the instructions to make ‘feature X’ (whatever that might be—something affecting the way your ears are constructed, for instance). The point is that the normal gene inherited from the other parent still carries the normal instructions to make X—so your X (e.g. ears) will generally be OK. But what happens if you inherit the same defective gene from both parents? Now you have no instructions to make normal X—so your X will now be defective (see Mutation Inheritance).

Mutations have accumulated since the Fall, causing many human diseases.

This explains why, when two people marry today, their children rarely show mutational defects. The point is that even though each parent carries hundreds of mistakes, and passes many on,12 the mistakes carried by each parent are not usually the same sets of mistakes. Because a husband and wife usually have parents with quite different genetic backgrounds, they will have significantly different sets of mistakes. So any defective gene inherited from one parent will normally be ‘covered up’ or ‘compensated for’ by the normal gene, carrying the normal instructions, passed on from the other parent.

Sometimes, in this fallen world, even when husband and wife are not closely related, it will just so happen that two of the same mistakes will pair together in the genes for one characteristic—i.e. the same mistake will be inherited from each parent, a tragic, but relatively rare situation.

But brother and sister have the same parents, i.e. the sources from which they obtain their mistakes are the same. So there is a rather high chance that the offspring of a brother–sister union will inherit at least one pair of genes in which the same mistake is present from each parent.13 This is why there is such a high chance of deformities and other defects showing up if brother and sister procreate.

People who are closely related, but less so than brother and sister (such as half-brothers and half-sisters), will have a lesser, but still substantial, chance of their offspring having such deformities. The closer the relatedness, the bigger the risk. So it makes biological sense for there to be legal and moral prohibitions against even half-siblings intermarrying.

The punch line

So how is this relevant to Cain’s wife? Simple. Since going forward in time means that a population will have more and more mistakes, going backward in time means that there are fewer and fewer such mistakes. Ultimately, one could extrapolate that back to a situation in which there were no defects. This makes sense in a biblical framework of understanding, since the first man and woman, created in a perfect world before it was corrupted by sin, would not have had any defective genes. Remember, God pronounced His original creation ‘very good’ (Genesis 1:31). After the Fall (Genesis 3), such copying mistakes could now arise. But it would take time—many generations, involving hundreds of years—for the mistakes to accumulate (add up) to a level at which it would be a significant risk for brother to marry sister.

In other words, Cain, or any of his brothers, could have married his sister (or niece, or any other close relative) without any biological problem. Even though only Cain, Abel, and Seth are mentioned by name, the Bible says clearly (in Genesis 5:4) that Adam and Eve had “other sons and daughters”. And we have already seen that such intermarriage must have occurred, since there were only two people in the beginning.

Remember that all this is referring to lawful, monogamous marriages before God. We will cover the moral issues shortly.

Biblical support

Starting the human race off with two people, as God chose to do, means logically that there must have been intermarriage between close relatives originally, in order for humanity to multiply and fill the earth (Genesis 1:28).14

But there is separate biblical support of another kind. Abraham, who lived some hundreds of years after the Flood (which was some 1,700 years after creation), was still able to marry his half-sister, Sarah—and there is no hint of any biological defects in the offspring.

So why didn’t God condemn Abraham and his wife? Hadn’t they broken the law against half-siblings marrying each other? Not at all. That law was only proclaimed hundreds of years after Abraham lived—at the time of Moses. It’s helpful to remember that things are right or wrong not on the basis of our opinion, but based upon what the Creator determines. And how do we know what His requirements are?

Through His revealed standards of moral absolutes to mankind, through His written Word, the Bible.

God changing His mind?

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. This might have been particularly important in the case of the children of Israel (to whom the Mosaic Law was given). They were a genetically ‘isolated’ population; they were told to avoid intermarriage outside their own group (unless the person converted to worshipping the true God of Israel). So there was an increased likelihood of close relatives marrying—which is why the prohibition was necessary. Out-marriage would otherwise tend to ‘dilute and delay’ the effects of the accumulating mutations. Preserving the Nation of Israel was vital, because from them would come the promised Messiah, the ‘seed of the woman’ (Genesis 3:15).

But what about the land of Nod?

Some understandably bring up the fact that after Cain slew Abel, there are indicators of many other people around. Referring to Cain’s exile, the Bible says that “the Lord put a mark on Cain so that no one who found him would kill him” (Genesis 4:15). And it says that he went to the “land of Nod” and “built a city” (Genesis 4:17). Often people read the passage as saying that he found a wife from among the inhabitants of Nod. However, the Scripture does not actually say that, it says (after mentioning that he went to live in that land) that he ‘knew’ his wife (in the sense of sexual relations). For all we know, the land of Nod may have been totally empty before Cain moved there—and he may have moved there with his wife, rather than meeting her there.

Furthermore, the Hebrew word (עִיר îr) translated as ‘city’ does not have the meaning that we might think with our modern understanding that entails many tens of thousands of people. The Hebrew word applied to a walled town or even something as small as a protected encampment.

But in any case, these are moot points, since it can be shown that there was plenty of time for a substantial population to have built up on Earth before Cain killed Abel—well over a hundred years. Cain was the first child born to Adam and Eve, and he appears to have been conceived shortly after the Fall, which was itself likely to have occurred only a few days or possibly weeks after the Creation. (Eve did not fall pregnant before the Fall, even though she and Adam were presumably healthy individuals in a perfect world and had been commanded to be fruitful and multiply.)

Seth appears to have been a replacement for Abel (Genesis 4:25), and Adam was 130 years old when Seth was born. So this means that by the time Cain killed Abel and went into exile, nearly 130 years had likely passed. (Given Cain’s age, even in those days of 900-year lifespans, it is highly likely that he had already been married for a long time prior to his migration to Nod.) If we assume that the first generation of Adam and Eve’s children could have had their own children 25 to 30 years after creation, there would be time for another 3–4 additional generations, with the numbers increasing exponentially each time.

This population build-up would have been the result of intermarriage between Adam and Eve’s children—as mentioned earlier, Genesis 5:4 tells us they had sons and daughters other than those named in the text. We do not know how many sons and daughters they had, but the more it was, the more quickly the numbers would have built up in later generations. A footnote to Whiston’s translation of The Works of Josephus, a Jewish historian, says that “the number of Adam’s children, as says the old tradition, was thirty-three sons and twenty-three daughters”.15 Whatever their exact number, it is obvious that there could have been a substantial population, perhaps even dispersed among many different settlements, within those 130 or so years. The ‘city’ Cain built may have been one more to add to the several that already existed.

Some state that for Cain to be fearful of retribution (Genesis 4:14) there must have been other people around. And of course there would have been, as explained above. However, it is interesting to ponder who would have any interest in avenging the death of Abel and thus posing a threat to Cain, unless it were Abel’s relatives. So the fact that all people at that time would have been relatively closely related to Abel (and Cain, and each other) may possibly make even more sense of the text.

Summary and conclusion

  • The Bible without any doubt teaches that God chose to start humanity off from only two people. This means that in the first few generations, marriage had to be between extremely closely related people, including at least one brother–sister union. The Bible says that Adam and Eve had daughters as well. Cain could have married his sister, or niece.
  • The biological problems caused by such unions today come from a progressive accumulation of genetic defects since the Fall. An originally perfect population would not have had any such problem.
  • The Bible teaches that even Abraham, living a long time after creation, was still able to marry his half-sister, Sarah, without any hint of biological problems in the offspring (Isaac). In doing so he was not breaking God’s Law. The Law of Moses forbidding intermarriage between close relatives was not given until centuries after Abraham.
Published: 29 March 2022

References and notes

  1. Being descended from Adam is the reason we need salvation anyway, as we have inherited his fallen nature. Return to text.
  2. Grigg, R., Darwin’s quisling, Creation 22(1):50–51, 1999; creation.com/kingsley. Return to text.
  3. Trial transcript: The World’s Most Famous Court Trial, the Tennessee Evolution Case, Bryan College (reprinted original edition), p. 302, 1990. Summary, including this incident at: bryan.edu/college-history/scopes-trial. Return to text.
  4. Batten, D. and Sarfati, J., 15 Reasons to Take Genesis as History, Creation Book Publishers, US, 2006; creation.com/15r. Return to text.
  5. Called a ‘show’ in that part of the world. Return to text.
  6. See also Sarfati, J., Loving God with all your mind: logic and creation, Journal of Creation 12(2):142–151, 1998; creation.com/logic. Return to text.
  7. Sarfati, J., DNA: marvellous messages or mostly mess? Creation 25(2):26–31, 2003; creation.com/message. Return to text.
  8. The rare evolutionist who faces up to the obvious difficulty that, if we had been around for a very long time we would be carrying an impossible load of mutations, often proposes selection to solve the problem. But most mutations are on average only slightly harmful and thus natural selection cannot ‘see’ them to eliminate them. These mutations are like rust on a car; no individual spot will stop the car, but enough rust spots inevitably will. Also, there are so many mutations that they are inexorably accumulating, generation by generation. This is an ever-increasing problem for any population. Geneticist Dr John Sanford has described this problem for evolution and its long ages in Genetic Entropy & the Mystery of the Genome, FMS Publications, US, 2005; see creation.com/sanford. Return to text.
  9. Some defective (mutated) genes are harmful even if the person only has one of them. This is much rarer, and such genes are more likely to be eliminated by natural selection (the person dies before reproducing). Return to text.
  10. The genetic system is incredibly complex, and this will inevitably be an oversimplification, though not misleading in its essence. Return to text.
  11. This is the important hormone that controls blood sugar levels. Return to text.
  12. We have about 25,000 gene pairs (which code for proteins) with one gene (allele) of each pair coming from each parent. So we each copy, and pass on, only half of our genetic information to each child, though it is a ‘different half’ each time (identical twins result from a natural cloning process at the first cell division of the new embryo). With half from each parent, the child then has a full complement. Return to text.
  13. Although there is only a one-in-four chance with any particular gene locus, with hundreds of possible mutations around, there is a high chance that at least one will be inherited from both parents. Return to text.
  14. Remember that the word ‘replenish’ in this verse in the King James Version (AV), in the English of that day, simply meant ‘fill’—just as the Hebrew word does. See Chapter 3 (on the gap theory). Return to text.
  15. Josephus, Flavius, (translated by William Whiston, A.M.), The Complete Works of Josephus, Kregel Publications, US, p. 27, 1981; creation.com/s/10-2-540. Return to text.

Helpful Resources

Who was Cain's wife?
by Dr Carl Wieland
US $0.60
Pocket booklet
The Genesis Account
by Jonathan Sarfati
US $39.00
Hard cover