by Ryan Pitterson, a review.
Judgement Of The Nephilim has close to 1000 reviews on Amazon and is the book on the topic, as I understand. Unlike in many similar works, the author (who is a Baptist, I think) uses only the Scriptures to support his theories and is highly critical of the apocrypha such as the (in)famous Book of Enoch.
Starting with the Garden of Eden and the Fall, JOTN takes us all the way through the antediluvian world, the story of Cain and Abel, the flood and ends with the victory of Jesus Christ on the cross and the last battle. The author argues that the first Nephilim were the descendants of the fallen angels and women of the Cain's family, that this unnatural mixing led to the corruption of human DNA to such a degree that the flood was necessary to wipe the mutant offspring out, since Jesus could only be born of a fully human woman.
About the time of the Great Flood only Noah and his family were genetically pure, but the wife of Ham had some Nephilim genes which led to the reappearance of giants after the Flood, though their bloodlines were further diluted. However, they spread through the whole of the Middle East with an especially high concentration in Palestine (the land of Canaan) and thus the military campaign of the ancient Hebrews to retake the Promised Land was a total war by necessity.
Ryan Pitterson argues that modern historians who decry "the genocide" which supposedly took place, fail to understand that the Israelites had to deal not with human beings but with giant bloodthirsty monsters threatening the whole of mankind and it was only because God fought on their (ancient Israel's) side that they succeeded in more or less wiping them out, with the last of giants being Goliath and his relatives.
Despite their military successes, early Hebrews became thoroughly corrupted by the Canaanite religion (worshiping the spirits of pre-flood Nephilim, witchcraft, necromancy etc) which led to further problems, yet Jesus Christ emerged victorious in the end. Still, in the last days the fallen angels will return to Earth along with the Nephilim spirits and try to corrupt the humanity again, but the last battle will reclaim the planet for Christ.
The book is rather lengthy (443p.) but well-written, engaging, thought-provoking, and quite sobering. It has some drawbacks, though, in my opinion. The author's theology is quite orthodox and traditional but being a Baptist he does talk about things like Rapture and the Millenial Kingdom, which many other churches disagree about. He is rather repetitive at times, quoting Scripture at length, and then quoting the very same passage but longer on the next page. His theories about pre-Flood world and the identity of the angelic ruler of it are just that, theories.
The part of the book which deals with Noah and his children and what happened later is much better researched simply because there is much more written about in the Bible (Mr. Pitterson also quotes various Victorian and early 20th century theologians at length, btw).
If you take his theories at face value then you should ask yourself whether modern genetics and especially genetically modified organisms and all research on these matters is something which could better be forbidden.
I would recommend this book to anyone interested in this topic.