ANSWER: The phrase “sons of God” refers to those men who “walked with God;” those who conducted themselves as His children. The same is said of Christians today (I John 3:1). The “daughters of men” refers to those women not counted among His children. The passage in question states simply that men who previously followed God took wives of women who did not follow God.

Certainly, the phrase “sons of God” cannot refer to angels, since heavenly beings are not given in marriage (Matthew 22:30).