John Calvin in his commentary on Genesis 6 defends the position that the “sons of God” are the descendants of Seth. Here he responds to a potential objection and illustrates the way in which Scripture speaks both of eternal election and external calling:

“Should any one object, that they who had shamefully departed from the faith, and the obedience which God required, were unworthy to be accounted the sons of God; the answer is easy, that the honour is not ascribed to them, but to the grace of God, which had hiterto been conspicuous in their families. For when Scripture speaks of the sons of God, sometimes it has respect to eternal election, which extends only to the lawful heirs; sometimes to external vocation [calling], according to which many wolves are within the fold; and though, in fact, they are strangers, yet they obtain the name of sons, until the Lord shall disown them.”