Dear Claire:

Angels are pure spirits; they have no material bodies. We know from the Bible that sometimes God allows angels to appear to us as human beings, and thus have a form of a human body, but they are still not biological beings.

Thus it is impossible for fallen angels to have impregnated anyone. While they might appear in human form, they do not have the biology to impregnate anybody. Only God can impregnate a woman outside of the normal biology.

Here is the Navarre Bible Commentary on the Genesis passage:

The Navarre Bible Commentary gives a good explanation of this passage:

Alluding perhaps to a myth in vogue in ancient times, to the effect that giants were the offspring of women who mated with beings of higher order, the sacred writer is stressing here the headway that sin and disorder have made. In this passage we are told that God put a limit on man's lifespan as a punishment for sin.

We cannot quite work out what the expression "sons of God" means here. Jewish tradition and some ancient Christian writers read it as meaning fallen angels; but that explanation does not fit in with the spiritual nature of angels. Therefore, it has been interpreted as meaning good men, the descendants of Seth who indiscriminately took as wives descendants of Cain, here called "daughters of men". This is the explanation given my St. Augustine (De civitate Dei, 15, 23), St. John Chrysostom (Homiliae in Genesim, 22, 4; St. Cyril of Alexandria (Glaphyra in Genesim, 2, 2) and other Fathers. Mankind's moral decline on account of pride and abuses of marriage prepares the way for the upcoming account of the flood.

It is interesting that today, in the 21st Century, mankind has morally declined on account of pride and profound abuses to marriage (vis-a-vis, domestic violence, divorce, abortion, incest, fornication, adultery, concubinage, etc.)

Bottomline: the most logical and probably meaning of this passage is that the term "sons of God" refer to the descendants of Seth, and the "daughters of men" refers to the descendants of the evil family line of Cain. The good family line of Seth, corrupted and began to marry from the evil family line of Cain. This would have happened only with a societal moral decline.

As a result, the world became so evil that God destroyed all the earth except for Noah and his family.

The passage in Jude merely says that the angels sinned; Jude is speaking of the rebellion of Lucifer and his cohorts. The Church teaches that the sin the fallen angels committed was Pride.

The idea of the angels committing a sin of impurity was a common belief among many Jews and survives to us today from the apocryphal Book of Enoch. The writer refers to this myth not to say the myth is true, but to make a rhetorical statement about the gravity of sins and the severity of the punishment they receive.

There are several rhetorical devices used in the Bible. Another one is by St. Paul who mentioned "baptism of the dead". St. Paul was not endorsing this nonsense idea or teaching it in any way. He was merely using a common folklore known by the people he was preaching to in order to make a point.

God Bless,
Bro. Ignatius Mary