Genesis does not say Cain and Abel (and later Seth) were the only three children of Adam and Eve. You are assuming Adam and Eve had no other babies. Adam was 130 years old when Seth was born. Eve surely bore more than three children in 130 years. There are no offspring of Abel. Cain killed him before the mention of any second generation. Cain married a younger sister and so did Seth, who Eve explained was appointed by God to be the replacement for Abel. Cain and Seth married their own sisters, but at that time the human body was in the original form (created to last forever, before the fall, before vast generations of degeneration) and siblings reproducing with each other was not what it would be currently.
The very best way to figure out what is in Genesis or any book of the Bible is to pray for the wisdom to discern its meaning, read it for yourself, read it all the way through, setting aside thirty minutes a day. The Living Word explains itself but you must read it all and read it for yourself and never think that a single passage can be fully appreciated strictly on its own.
"at that time the human body was in the original form (created to last forever, before the fall, before vast generations of degeneration) and siblings reproducing with each other was not what it would be currently."
What empirical evidence do you have to support this assertion?
Does it really say they married their sisters? Or is it implied? Did I miss it somehow? (not Sacrcasm, just curiosity on my part). I think I remember there being somethink in there about the women not being part of the family. I have to go back and reread. Thanks...see you’ve got me reading the Bible now! Sometimes things happen for a reason :)