NIV Genesis 6:1 When men began to increase in number on the earth and daughters were born to them,
2 the sons of God saw that the daughters of men were beautiful, and they married any of them they chose.
3 Then the LORD said, "My Spirit will not contend with man forever, for he is mortal; his days will be a hundred and twenty years."
4 The Nephilim were on the earth in those days-- and also afterward-- when the sons of God went to the daughters of men and had children by them. They were the heroes of old, men of renown.
5 The LORD saw how great man's wickedness on the earth had become, and that every inclination of the thoughts of his heart was only evil all the time.
So who are the "sons of God" referred to in Genesis 6:2? Is this a reference to creatures who are not human, as opposed to those of "man"? Are they super-human creatures, more than man, but less than angels? Or perhaps superheroes such as X-men, spiderman, or superman are myths who find their basis in real people who existed long ago. There have been many interpretations of this text. One theologian, William VanGemeren, believed the "sons of God" were indeed angels who had taken human wives, and their offspring were known as the "nephilim". The sin involved here would have been angels leaving their proper heavenly abode. Meredith Kline took them to be a reference to earthly kings, those who represented God. The sin in view here would be the implication of polygamy in verse 2. The "nephilim" were offspring who were tyrants who propagate violence. However, the most likely interpretation is that the "sons of God" were simply those who came from the godly line of seth. The sin in view here is primarily that of people being "unequally yoked", as godly people were marrying the ungodly. The reference to Nephilim are not necessarily related to the "sons of God", but were simply men who were excessively violent. This interpretation seems to fit more naturally with the tenor of the Genesis narrative. The obvious focus of Genesis 4-5 (Cain & Geneology) is that of the development of two distinct lines. The main point of this passage then is not to be used as a proof-text for the legitimacy of superheroes. Instead, it fits with the overall theme of Genesis leading up to Noah, which is to show the state of the world prior to the flood, as being one of man's increasing depravity.