By way of explanation as to God’s anger, at least in part, the problem is recorded as, “the sons of God” taking wives of as many of the “daughters of men” as they desired. Verse four seems to indicate that the offspring of these relationships were quite special, reporting them as, “mighty men which were of old, men of renown.” There are at least two schools of thought on the matter. I will give you both.

The most common interpretation is that the “sons of God” were fallen angels who came to earth and began cohabitating with women. The biblical evidence in support of this argument would be that the term “sons of God” is used three times in the book of Job to mean angels (1:6; 2:1; and 38:7). Additionally, the New Testament book of Jude adds some clout to this argument. Verse six speaks of “…angels which kept not their first estate, but left their own habitation” having been “reserved in everlasting chains under darkness unto the judgment of the great day.” So there was a particularly noteworthy class of evil angels who have been prevented from ever again interfering with the affairs of man because of some past, infamous sin.

But in all honesty some great men of God have disagreed with this conclusion. I remember hearing Dr. J. Vernon McGee on the radio years ago disagree. His argument was thought provoking. As I recall he stated that they could not be angels because angels cannot reproduce. He referred to Jesus’ discussion of the husband and wife relationship in heaven after death. Matthew and Mark both record Jesus as explaining that men and women “neither marry, nor are given in marriage, but are as the angels of God in heaven” (Matthew 22:30; Mark 12:25). Dr. McGee, as I recall, believed they weren’t angels but faithful men of God who fell into gross immorality and disobedience by marrying unsaved women – and lots of them. I believe he is right. Some additional support for this conclusion might be that saved men are called the “sons of God” six times in the New Testament (John 1:12; Romans 8:14, 19; Philippians 2:15; and 1 John 3:1-2).

There have been only two lines of men since Cain killed Abel: The ungodly, represented by Cain and the godly represented by Seth. If you study the lines, actions and statements of God toward these two lines, I believe you will see that relationship coming forward to the flood and causing great problems.  Backslidden believers of God seeing unsaved women in all sorts of whorish undress and the rest is history...

To be honest it doesn’t really matter. In fact I have heard it wisely said that where God is silent we are fools to speak. But we are men and “It is the…honour of kings is to search out a matter” (Proverbs 25:2). God has spoken, however, on one particularly important issue, “…ye must be born again” (John 3:7).