Yes — at the earliest stage of human history, marriage between close relatives was acceptable because humanity was still genetically pure.
Les Feldick teaches that since Adam and Eve were the only people created, their sons had to marry their sisters for the first generation or two, and this caused no problems because the human race was so pure genetically. Even 2,000 years later, Abraham married his half-sister Sarah, and Isaac was healthy. God did not prohibit close-relative marriage until sometime after Abraham, when the gene pool had weakened enough that such unions began to cause genetic problems.
Genesis 4:17 — This verse mentions Cain's wife, which raises the question of where she came from when only Adam and Eve's family existed.
Genesis 20:12 — Abraham's own words show he married his half-sister Sarah, proving close-relative marriage was still practiced long after the beginning.
Leviticus 18:6 — This later command shows that God eventually restricted marriage to near kin, marking the change from the earlier period.
The biblical record opens with a single human couple: “And Adam called his wife's name Eve; because she was the mother of all living” (Genesis 3:20). After Cain kills Abel, Genesis 4:17 says, “And Cain knew his wife; and she conceived, and bare Enoch: and he builded a city, and called the name of the city after the name of his son, Enoch.” With no other human beings created, this wife could only have come from Adam and Eve's own children. The early chapters of Genesis give no command against close-relative marriage; instead, the practice continued for centuries. Abraham told Abimelech about Sarah: “she is the daughter of my father, but not the daughter of my mother; and she became my wife” (Genesis 20:12). At that point in the text, this union is not condemned. Only later, in the Law of Moses, does God explicitly restrict marriage to near kin: “None of you shall approach to any that is near of kin to him, to uncover their nakedness: I am the LORD” (Leviticus 18:6). This later command demonstrates that what was once not forbidden later became a boundary for Israel.
Les Feldick approaches the question from the standpoint of genetic purity. He reminds his students that beginning with Adam and Eve there was one race of people, so when someone asks, “Where did Cain get his wife?” the answer “only follows that brothers married sisters for the first generation or two.” That was no problem, Les says, because the human race was “so pure genetically.” He then moves forward to Abraham, about 2,000 years after Adam. Even though the genetic pool was already beginning to weaken, Abraham still married his half-sister Sarah, and Isaac was perfectly fine. Les concludes that God did not place a taboo on close-relative marriages until sometime after Abraham, when the declining gene pool made such marriages risky. He also uses genetics to explain related phenomena, noting that crossing long-isolated pure bloodlines produces stronger hybrids, which he sees reflected in the unusually vigorous descendants produced when the line of Seth intermarried with the line of Cain.
Les says the answer is simple: there were only Adam and Eve, no other people. So Cain's wife had to be one of his sisters. Brothers married sisters for the first generation or two, and it caused no problems because the human race was so pure genetically.
Les teaches that the human genetic pool did not remain pure. By the time of Abraham — about 2,000 years after Adam — the genetic pool was already weaker. God did not put a taboo on marrying close relatives until sometime after Abraham, because by then such marriages could cause the genetic problems we recognize today. Abraham himself married his half-sister Sarah, and there was nothing wrong with Isaac.
Les also emphasizes that God's original plan from the Garden of Eden was one man married for life to one woman. The early permission for close-relative marriage was not a different moral ideal; it was a practical matter of a pure genetic condition that made such marriages harmless. When that condition changed, God later placed restrictions on close relatives.
Who Did Cain Marry? & The Mystery of Enoch (Genesis 4-5 Bible Study)
Hello, and welcome to Through the Bible with Les Feldick. An Oklahoma rancher and farmer, Les Feldick has taught home-style Bible classes for twenty years in Iowa, Oklahoma, and Texas. Les Feldick's unique style of Bible teaching has made the books of the Bible come to life. When Les is teaching, it's so interesting, people say, the time seems to fly by. And now, here's Les Feldick.
Abraham's Half-Sister Marriage
Les uses Abraham's marriage to his half-sister Sarah to show that close-relative marriage was still accepted with God's blessing 2,000 years after Adam, with no harm to Isaac.
Your Body Is the Temple of the Holy Spirit — 1 Corinthians 6:19
Of course that caused problems in the early church, and so that was finally pushed out the back door. But see all these things entered in, and so Paul is answering their question that it's not good for a man to touch a woman or embrace her, or get involved with her enough to excite the basic instincts of her or him, but he is not saying that they can't get married.
Cain's Wife and the Pure Gene Pool
Les answers the question of Cain's wife by explaining that brothers married sisters in the first generations because Adam and Eve were the only people, and the human race was too pure genetically for problems.
Crossing Bloodlines and Hybrid Strength
Les draws on genetics to show that crossing long-isolated, relatively pure bloodlines produces stronger offspring, providing background for why early genetic mixing could be positive.
Mighty Men and Intermarriage Results
Les notes that descendants of the Seth/Cain intermarriage became mighty, ambitious, and energetic men, illustrating the genetic effect he described.
God's Original Marriage Plan
Les reminds listeners that God's original plan was one man married for life to one woman, which remains the biblical concept even after later restrictions on close relatives.
Intertwined Families
Les points out that even later, Abraham's wider family line remained intertwined with close relatives while being forbidden only from marrying Canaanites, showing the continuing pattern of family intermarriage.
Genesis 4:17: And Cain knew his wife; and she conceived, and bare Enoch: and he builded a city, and called the name of the city after the name of his son, Enoch.
This verse raises the question of where Cain's wife came from, and Les answers that she was one of Adam and Eve's close descendants.
Genesis 20:12: And yet indeed she is my sister; she is the daughter of my father, but not the daughter of my mother; and she became my wife.
Abraham's own words reveal that Sarah was his half-sister, showing close-relative marriage was still practiced.
Leviticus 18:6: None of you shall approach to any that is near of kin to him, to uncover their nakedness: I am the LORD.
This later law shows God eventually restricted marriage to near kin, ending the earlier period of acceptance.
Genesis 6:4: There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
Les cites this when describing genetic intermarriage and the unusually strong descendants that resulted.
Yes — according to Les Feldick, since Adam and Eve were the only people created, Cain's wife had to be one of his sisters. Brothers married sisters for the first generation or two, and that was not a problem because the human race was genetically pure.
Les says God did not place a taboo on marrying close relatives until sometime after Abraham, because by then the genetic pool had weakened and such marriages could produce genetic problems. The later biblical commands restricted marriage to near kin.
Les points out that Abraham married his half-sister Sarah with God's blessing, and Isaac was born healthy. This was before God's later restrictions on close-relative marriage.
Les teaches that God's original plan was always one man for one woman in a lifetime marriage. What changed was not the moral ideal but the genetic condition of humanity, which made early close-relative unions harmless and later ones harmful.
Watch the Teaching: Who Did Cain Marry? & The Mystery of Enoch (Genesis 4-5 Bible Study)