The term ‘sons of God’ is used in Genesis 6:2 and 6:4, where it is stated “the sons of God saw that the daughters of men were beautiful. And they took wives for themselves; whoever they chose”. The account states that they had sexual relations, and as a result the daughters of men “bore children to them”. So, who are the ‘sons of God’?
Variation in interpretation
There are three primary interpretations of this passage. Each view is supported by its own group of knowledgeable scholars. Their lengthy arguments are based on a multitude of technical and logical considerations, including the original Hebrew words and grammar used, the words chosen to translate the passage into other ancient documents, and references in other Biblical and extra-Biblical literature. I can only briefly summarize their arguments here.
Angels
First of all, there is one interpretation that the ‘sons of God’ were angelic beings who rebelled against God and fell from grace. They somehow assumed human form and were able to procreate. And their offspring were the Nephilim, a term often translated as ‘giants’. Two significant problems with this view are that nowhere else in the Bible do we read that angels marry. In fact, Jesus taught that angels do not marry (Mark 12:25). A second major problem with this view is that this passage immediately precedes the flood. And the context makes clear that the flood is a result of the sins of mankind, not angels (Genesis 6:5-7).
Godly descendants
A second interpretation views the phrase ‘sons of God’ as referring to the godly descendants of Seth, as opposed to the ungodly female descendants of Cain. Their sin would then be one of religiously mixed marriages between the godly and the ungodly. One significant problem with this view is that there doesn’t appear to be any precedent for interpreting the words in this way. Secondly, it doesn’t explain the meaning of the Nephilim. So, how would human marriage result in giant offspring?
Powerful individuals
The third view looks to the surrounding cultures for the meaning of ‘sons of God’. It was common at the time to view powerful individuals, including kings and nobles, as being descended from the gods in some manner. The theory is that certain men became powerful and corrupt, and began to think of themselves as godlike, doing whatever they wanted to those less powerful and taking wives whenever it suited them. In this theory, their offspring were called great/mighty men or princes, which is the meaning of Nephilim when combined with the word ‘gibborim’, which is also found in the text. So this view best fits the context of the flood, where evil thoughts and actions are about to be judged by God. It also aligns more closely with what the rest of the Bible teaches about the pride of men and nature of angels.