Question: Jesus clearly stated that angels do not marry, (Matt 22:30). So the “sons of God” in Genesis 6 who married the daughters of men were likely from the godly line of Seth.
Answer: Jesus stated that angels do not marry in heaven. Adding the “in heaven” words are important. ”They will be like the angels in heaven” (Matt 22:30). Angels who walked on earth with a material body were able to procreate. They did not come from the same stock as humanity, so we are not able to say they had a human body, but they had a body with all the necessary features that a physical body needs for life on earth. Angels in heaven are spirits and have no biological body, that’s why Jesus stated “angels in heaven”.
The Nephilim were a hybrid race that affected the human gene-pool. The Bible explains that the Lord went to some pains to get humanity back on track.