Genesis 6:1-4

The people on the earth kept on having lots of kids, and those kids grew up and kept on having more kids, so after some time there were lots of people on the earth. And some people had very pretty daughters. There were some men that everyone called the Sons of God . They looked at the pretty young women, then they picked out the women they wanted, and they married them. God looked at everything that was happening. He said, “I gave people their breath, but I will not let it stay in them for ever. They are just people. They will live for only 120 years.” Those men that were called the Sons of God, they slept with the pretty women, like men usually sleep with their wives, and then those women had kids called Nefalim. Those Nefalim kids grew up to be big, strong fighting men. They were the great fighters in the stories from a long time ago.