Cain and Seth’s Wives
By Wayne Spencer
One of the most common questions about creation and the Bible is regarding Cain. “Where did Cain get his wife?” The short answer would be that Cain married a relative, possibly a sister. When Cain was born, it says Eve said, "With the help of the Lord, I have brought forth a man. (Genesis 4:1)" I think we can infer that Cain was the first child. But it isn't totally clear what the sequence of children was after this. After 4:1 it says in 4:2, "Later she gave birth to his brother Abel." So we are not sure how much time went by between the birth of Cain and Abel. Then in Genesis 5:3 it says Adam was 130 years old when he had Seth. Then it says Adam lived another 800 years and had other sons and daughters (5:4). We are not told about the birth of the daughters. It is possible there could have been daughters born after Cain but before Abel. Or daughters could have been born after Abel was born but before Seth was born. We don't even know how many years Cain and Abel lived before Abel was killed. After the death of Abel, it's possible there may have been enough time that Cain could have already had one or more sisters. I suspect there was some period of years after killing Abel that Cain lived unmarried, but that is only my guess. But it seems likely Cain married a sister.
I think we should consider Seth in this issue as well, and some things about our genetics. The descendants of Adam and Eve’s third son, Seth, are listed in Genesis chapter 5. In that chapter it says Seth became the father of Enosh when he was 105 years old. Enosh is probably the first born son (of Seth). It also says in Genesis 5:7 that Seth lived a total of 807 years. We are not told how long Cain lived. After murdering his brother, Cain moved away from Adam and Eve to an area called Nod.
Cain and Seth may have had a problem getting married that single men today do not have. They may have had to wait for women to be born and grow up! So if Seth and Cain would have had lifespans like us today it may not have been feasible for them to get married before they were too old to have children. But since Seth lived to be over 800, I think we can assume Cain had a long lifespan as well. Thus, Cain and Seth had plenty of time to get married, but they probably had to wait for some years. They could have married a sister, or possibly a cousin. We don’t know how many children Adam and Eve had but it could have been many.
Why was it ok for Cain and Seth to marry sisters? First, the Law of Moses was not in force at the time of Adam and Eve, so apparently God did not forbid it. Second, considering genetics, at that time early in the history of the human race, there would have been few mutations and so genetic disease from mutations would have been unlikely. Today, two close relatives are likely to have mutations that match-up in position in their DNA and this could cause serious mutaitions. This is not likely for people from different unrelated families. Adam and Eve were both supernaturally created with perfect DNA which had all the genetic variation needed by the human race already built-in. So, it was acceptable at that time for Seth and Cain to marry a close relative. But it was forbidden later under the Law of Moses (see Leviticus 18). Today it could lead to genetic disease or deformities in the children, so it would be very risky.