Originally published in the Genesis Apologetics FAQ
After Cain killed his brother Abel, God said to Cain, “Now you are under a curse and driven from the ground, which opened its mouth to receive your brother’s blood from your hand. When you work the ground, it will no longer yield its crops for you. You will be a restless wanderer on the earth” (Genesis 4:11–12).
To this, Cain replied, “My punishment is more than I can bear. Today you are driving me from the land, and I will be hidden from your presence; I will be a restless wanderer on the earth, and whoever finds me will kill me” (Genesis 4:13–14).
God responded, “Not so; if anyone kills Cain, he will suffer vengeance seven times over.” Then the Lord put a mark on Cain so that no one who found him would kill him” (Genesis 4:15–16).
So just what exactly was this “mark” that God put on Cain? The Hebrew word translated “mark” means a “mark, sign, or token,” leaving many to speculate what the “mark” may represent in this context. At a minimum, we know from the text that it was some type of (likely external) visible sign so that others would identify and not kill Cain.
Some people (especially in the past) mistakenly believed this mark to be dark skin. Racists used this perspective to justify African slavery and discrimination against people with dark skin. But this position is completely unbiblical. Nowhere in the Scriptures is the Hebrew word for mark (owth) used to refer to skin color. Cain’s curse was Cain’s curse—not an entire people group. The text does not say that Cain’s curse was passed on to his descendants. Whatever the mark was, it was certainly not generational, but applied only to Cain.
Cain and His Wife
Many people have asked, “Since Genesis 1–4 only records two children of Adam and Eve (Cain and Abel), and all humanity descended from Adam and Eve, then where did Cain’s wife come from? Related to this, if Cain married a relative, then doesn’t this indicate incest? And if Cain did marry a relative, wouldn’t we expect their offspring to suffer degenerative effects?
Some try to answer this by saying that Cain’s wife came from a race of Pre-Adamic humans who were around before Adam and Eve. This explanation doesn’t fit within Scriptures, which are clear that Adam was the first man created (Genesis 2:7,18–19; 1 Corinthians 15:45). Eve was also given her name because she was the mother of all living(Genesis 3:20). These two facts rule out the idea of some Pre-Adamic race from which Cain chose a wife.¹
The simple answer to this challenge is found in the very next chapter. Genesis 5:4 says, “After he begot Seth, the days of Adam were eight hundred years; and he had [other] sons and daughters.” Because Adam lived a long life and God had promised Eve that he would greatly multiply her conception (Genesis 3:16), many people could have existed at the time when Cain killed Abel (a conservative estimate is that 32,000 people could have been alive at that time this event occurred). Jewish tradition states that Adam had 33 sons and 23 daughters!
But what about incest? If Cain married his sister, he did not commit incest because incest did not become a crime until thousands of years later. Intermarriages between brothers and sisters were permissible until God later gave the Book of Leviticus (chapter 18) which condemned these relationships. After all, Abraham married his half-sister with no problems. Since that time, mutations have accumulated exponentially in humans.
- Don Stewart, Where Did Cain Get His Wife? Blue Letter Bible