Why did God allow Angels or Demons to have relationships with Human Females and produce offspring?
That is a stupid interpretation and it is YOUR interpretation. To put it mildly I think ST Thomas Aquinas would call you an asssss (but nicely ) Reply Obj. 6. As Augustine says (De Civ. Dei xv): Many persons affirm that they have had the experience, or have heard from such as have experienced it, that the Satyrs and Fauns, whom the common folk call incubi, have often presented themselves before women, and have sought and procured intercourse with them. Hence it is folly to deny it. But Gods holy angels could not fall in such fashion before the deluge. Hence by the sons of God are to be understood the sons of Seth, who were good; while by the daughters of men the Scripture designates those who sprang from the race of Cain. Nor is it to be wondered at that giants should be born of them; for they were not all giants, albeit there were many more before than after the deluge. Still if some are occasionally begotten from demons, it is not from the seed of such demons, nor from their assumed
The story isn’t true. It is pure myth, that was added for dramatic effect. There are no angels or demons. God is alone in the Universe. He created all things by himself. God said: “I am God, the Creator of all things. I alone stretched out the heavens; when I made the earth, no one helped me.” (Isaiah 44:24) Christians in particular believe that God has angels around him, some good some bad, but that wayward belief is rooted in Greek mythology. There are many foreign inserts in the bible. Read God’s commandments and laws and notice how he dealt with his people the Israelites and you will soon be able to separate the truth from the hocus pocus inserts.
The sons of God in those particular verses were not angels, even though the sons of God in the Old Testament most of the time, referred to the angels. In these verses prior to the flood, the sons of God were from the line that the Savior would come through. The sons of Seth. Only one, Noah was pure to the line of Seth, who was saved, with his family, from the flood. Righteous enough to carry the chosen line.The daughters of the sons of man were the common men, and not of the line to David, which Jesus would descend from, and be called the son of David. Mat 22:29 Jesus answered and said unto them, Ye do err, not knowing the scriptures, nor the power of God. Mat 22:30 For in the resurrection they neither marry, nor are given in marriage, but are as the angels of God in heaven. The angels are not sexual and are neither male nor female, on earth or in heaven. They were created nonsexual and they have not the power to change the way they were created.