I have studied over and over about Cain and his wife, and I have questioned where did Cain’s wife come from. What God has showed me that, there were people before Adam and eve, because, and remember Satan and his angels were thrown down from heaven, so they became flesh. Saying that Cain must have married his offspring would be saying that god allowed sin. Now I’m doing a study on Noah’s time. Please respond to my feedback, you might have a better insight. I’m always ready to learn and get close to God.
Someone might have showed you that, but it wasn’t God. His word indicates that Adam was the first man and Eve the first woman. Cain couldn’t have married one of his daughters but he could have married a sister or a niece. Remember, Genesis 5:4 tells us that Adam and Eve had other sons and daughters in addition to Cain, Abel, and Seth. Marrying a close relative was not a sin and in fact was his only option. This kind of relationship was not forbidden until much later. In fact Abraham married his half sister Sarah, Rebekah was Isaac’s niece, and a two of Jacob’s 4 wives were his cousins. All these unions had God’s blessing.