Ge 6:1-8
'Now it came about, when humans began to multiply on the face of the earth, and daughters were born to them, that men, created by God, saw that human daughters were beautiful; and they took women for themselves as they liked. So the Lord said, "My Spirit shall not strive with man forever, because he is indeed frail; his remaining time on earth shall be one hundred and twenty years." Arrogant men were on the earth in those days, and also afterwards, when men, created by God, came to the daughters of men, and they gave them children. Those were the masterful men of old, men of reputation.
So the Lord saw that the wickedness of humanity was great on the earth, and that every intent of the thoughts of his heart was only evil continually. The Lord was sorry that he had made man on the earth, and he was grieved in his heart. The Lord said, "I will blot out man whom I have created from the face of the land, from man to animals to creeping things and to birds of the sky; because I am sorry that I have made them." But Noah found favour in the eyes of the Lord.'
Notes
1. The term translated 'sons of God' means men, not angels, and here ironically emphasises man's creation in God's image.
2. The phrase 'his remaining time on earth shall be one hundred and twenty years' is the time to elapse between God's displeasure and his punishment, not the future lifespan of human individuals. The number 120 signified an extended completeness (12 x 10) that may be taken as the giving of opportunity to change one's ways.
3. The word translated 'Nephilim' or 'giants' should be translated 'arrogant men' or a synonym.
4. The word translated 'reputation' is also found in ch. 11 where it is recorded that those who wanted to make a name for themselves were thwarted by God.
6. The cause of the flood is man's actions- promiscuity, as well as injustice and violence, mentioned later- and also his thoughts, evil all day, every day. His uncontrolled sensuality and high-handedness signify complete absence of the spirituality that is due in God's special creation, created in his own image.
5. 'The Lord was sorry' is poetic exaggeration.
This passage, like the flood account, undoubtedly had value as a story myth, used by the ancients not as history but as moral framework. For today, it is end-time prophecy, rather than historic record. The comment 'they took women for themselves as they liked' may be supposed to refer to the present social norm. The passage can be taken as written in the past tense from a point in time after the end of this world.