The First Family’s Hard Question: Did Adam and Eve’s Kids Marry Each Other?
Larah Heinrich
Last night during our 45-minute family Bible study, my seven-year-old asked me a question that really made me stop.
“Mum, does that mean Adam and Eve’s children had to marry each other?”
Yes, they did. The Bible tells us in Genesis 5:4 that Adam “had other sons and daughters.” So when Cain needed a wife, he married his sister. There was simply no one else on earth.
John MacArthur explains that in the very beginning, God allowed this because the human family had to grow from one couple. The gene pool was still pure, so it wasn’t dangerous like it would be today.
Relevant Quote (from that sermon):
“He married his sister. … In that pristine, pure era of humanity, there were no mutant genes to cause the kind of problems that a decaying humanity brings upon itself… At this time, such was not necessary, and there would be no other place to get your wife than to marry your sister, which was perfectly within God’s purpose.”
https://www.gty.org/sermons/90-251/the-origin-of-society-part-1
But later God gave a clear command: “Don’t have sex with any of your close relatives” (Leviticus 18:6, CEV). These laws were given to protect us and keep families healthy. That’s why even today, marrying or having a relationship with a close family member is not what God wants for us.
The New Testament agrees. In 1 Corinthians 5:1 (CEV) Paul calls it a terrible thing — even people who don’t know God know it’s wrong.
The beautiful news is this: even though God’s commands are serious and breaking them is sin, we are not saved by keeping these laws perfectly. We are saved by grace through faith in Jesus Christ, who obeyed the law perfectly in our place. His grace doesn’t give us permission to keep on sinning — it forgives us and gives us the power to live in a way that pleases Him.
This is the big picture we’re teaching our children each night: God’s Word makes sense, it protects us, and every part of it leads us to Jesus.
Further Reading for Parents:
• Romans 1:18-32 (CEV)
• 1 Corinthians 5:1-5 (CEV)
• Not If, But When: Preparing Our Children for Worldly Images by John Perritt
These precious moments shared capture the heart and soul of motherhood, woven with faith, laughter, and meaningful lessons.
Sarah and Family
Loving Mum and Wife
Mum & Kids
Welcome to our little corner of honest family moments.
This is where I share the real conversations I’ve had with my children — the unexpected questions that pop up during our nightly Bible time, the awkward chats, the giggles, and the lessons we’re learning together.
Some moments make me smile, some stop me in my tracks, and many remind me how much I need God’s wisdom as a mum.
Whether you’re a parent trying to raise your children in faith, or you simply enjoy seeing God’s Word come alive in everyday family life, I hope these stories encourage you.
These aren’t perfect lessons — they’re real ones. Raw, sometimes messy, but full of grace.