There is a cosmic chess match going on. Good vs. evil. God vs. Satan. I starts in the first book of the Bible, Genesis. In the garden of Eden, Adam and Eve sinned after Satan tempted Eve. God delivered the first prophecy in Gen. 3:15. God, speaking to Satan says, "And I will put enmity between you and the woman, and between your offspring and hers; He will crush your head and you will strike his heel." Satan ultimately loses the war. He is defeated at Calvary. But he tries mightily to prevent the Savior, Jesus, from ever being born. The messiah can only be born of a pure, uncontaminated blood line.
In Genesis 6:1-4 Satan's fallen angels take human wives and produce the Nephilim, the giants. The interbreeding of fallen angels with humans threatened the possibility of the Messiah being born. If Satan could contaminate every human genetic line, he would win. But God knew his plan and thwarted it. Gen. 6:9b says "Noah was a just man and perfect in his generations, and Noah walked with God." Noah wasn't a perfect man, but his generations were perfect. His bloodline was uncontaminated by fallen angels. God reserved 8 people to repopulate the earth after the Flood. God cleansed the earth of the Nephilim in the flood, but they did it again after the flood. Gen 6:4 says "There were giants in the earth in those days, and also after that..."
In the Old Testament God tells the nation of Israel to totally destroy some tribes including women and children and animals. This seemed to be excessive to me until I understood the seed war. Those tribes were genetically contaminated. The fallen angels even procreated with animals, going after "strange flesh".
