The identity of Cain’s wife has long troubled Christians. David Instone-Brewer proposes a new way of thinking about the problem 


It’s a question often accompanied by a smug smile: “So who did Cain marry?” If the reply is: “His sister,” the usual response is: “That’s immoral!” And if the answer is: “Not everything in Genesis should be taken literally”, the follow-up question is: “So how do we know which bits of the Bible are true?” 

Here’s another possible answer. It fits the literal Bible text better than Cain marrying his sister and also fits with all current scientific findings.

Cain’s neighbours

Adam lived perhaps 30,000 years ago. We know genealogies in the Bible aren’t complete (compare Genesis 10:24 and Luke 3:35-36) and we know the Hebrew word for ‘father’ can also mean ‘ancestor’ (it’s translated both ‘father’ and ‘grandfather’ in 2 Samuel 9:7). But we don’t know how many people are missing in these genealogies. So let’s look at the rest of the narrative to try and fill in some of the details. 

Genesis 4:16-22 tells us that Cain went to the land of Nod, where his wife had children. He built a town, naming it after his son Enoch, and his children and grandchildren specialised in different professions including herding, musical instruments and tool-making. But we aren’t told who he married, who the people in his town were or why the land had a name. 

After being exiled from Eden, Cain was afraid, so God said: “anyone who kills Cain will suffer vengeance”. He also “put a mark on Cain so that no one who found him would kill him” (Genesis 4:15). But who was going to kill Cain? If Adam had another son who was bent on vengeance, Cain would perhaps have many years head start – so why was God concerned to keep Cain safe? 

The obvious answer is that others were living outside of Eden who didn’t appreciate a murderer living next door. They called their country Nod, and they provided the population for the town Cain built. This explains how Cain’s children could specialise – something that normally wouldn’t occur until many people cooperated together. 

The first human

This interpretation means there were other hominids living at the time. But these were merely intelligent animals – and not human. When God took Adam and gave him a spirit, something brand new happened. Genesis 2:7 tells us that God: “breathed into his nostrils the breath of life, and the man became a living being”. Adam was the first being, other than God and the angels, to have a spirit. This made him something completely new – a spiritual person who could know about God and communicate with him. 

The Bible uses ‘soul’ and ‘spirit’ in consistently distinct ways. The ‘soul’ (Hebrew: nephesh; Greek: psuchē) gives emotions and personality to humans and animals. But the word ‘spirit’ (Hebrew: ruach; Greek: pneuma) is only ever used in the Bible for humans, angels and God – it is our non-physical connection to God. While a baby grows: “the spirit comes to the bones in the womb” (Ecclesiastes 11:5, ESV). When we die: “the spirit returns to God who gave it” (Ecclesiastes 12:7), so the psalmist and Jesus said: “Into your hands I commit my spirit” (Psalm 31:5; Luke 23:46). 

Only direct descendants of Adam’s children inherited a human spirit

God didn’t need to breathe into Adam’s descendants – they inherited the human spirit from him, along with his propensity to sin. If Adam hadn’t sinned, the tree of life would have kept us alive forever, just as it will in the future (Revelation 22:2-5). As it is, he was expelled from the only place it grew, and without it he started to die, like any other living thing and like all of us who also sin (Romans 5:12). 

Spiritual beings 

Outside Eden, Adam, like Cain, met others who looked like him, but they didn’t have a spirit. When Cain and others took partners from among them, their DNA became part of our family tree – including a little DNA from Neanderthals that we’ve inherited. The others looked like Adam’s family, but only direct descendants of Adam’s children inherited a human spirit. 

This spirit gave us great advantages. Quite apart from a healthy inner urge to find God and seek his guidance, having a spirit makes us more empathic and able to cooperate. We are more altruistic than animals, even carrying out acts of self-sacrifice for the community and not just for our own family. We also cooperate better, using our different skills to find solutions and ways to adapt, which has helped us to survive famines and disasters. The children of those without a human spirit soon died out, like the Neanderthals, Denisovans and other groups before them. They didn’t have the same advantages as spiritual humans. 

It is theoretically possible that we might discover an isolated tribe of humans without a spirit. We’d recognise them because, like animals, they’d lack any interest in worship. They wouldn’t be atheists because they’d never conceive of a God to deny. If we told them about God, they wouldn’t be interested – or opposed to him – the subject would simply seem unimportant. However, every tribe we’ve discovered so far is spiritually minded.

The Bible doesn’t affirm or deny these details, and this explanation helps us understand the text. It explains why the land of Nod had a name, who Cain built a town for, how his children could specialise, who God protected Cain from and, of course, where he found a wife. 

I’m not expecting you to accept this straight away any more than I did at first. It goes against all the traditional interpretations I was brought up with. But I have to keep reminding myself that God didn’t give us traditions: he sent us his Word (Jesus), and his word (the Bible) to trust in.