I'm not sure what this intends but seems to be offered as an answer to Brian's question ("Do you think Satan is a personal being—a real individual entity, or more of a concept? If a concept, a concept of what?") I am assuming that the answer is intended to be the former.
Originally Posted by Dan Ross
However, this ignores the historical questions posed earlier in this thread, which must be asked here. They are a crucial set of questions since this passage clearly reflects an intertestamental development in how opposition to God is understood in Judaism.
There are stories in several apocryphal and non-canonical Second Temple Jewish texts of a contest between the Devil and God (note that in the Old Testament, for example in 1 Kings 18, the opposing parties are God and Ba'al and his followers). These texts tend to reinterpret and rewrite canonical stories in terms of Greek influenced dualism, expressed as the struggle between good and evil with evil personified in various forms of demons or the devil. That suggests we are dealing with historical development here, not ontology.
For example, in the 2nd century BC Book of Jubilees (17:15-18:16; see below), the Genesis 22 story of the Binding of Isaac is retold as a contest between God and Mastema (Heb: hatred, hostility), a Jewish intertestamental term for the prince of demons. Also in Jubilees 48:2-3, it is Mastema that seeks to kill Moses while in Exodus 4:24 it was God. Later (48:9), it is Mastema that confronts Moses rather than Pharaoh, and it is from Mastema that the Egyptian sorcerers derive their power. In other words, the biblical accounts are rewritten in terms of a dualistic conception of good and evil, with evil personified as demons or the devil.
Biblical and historical scholars conclude that Jude 9 was taken from the (now lost) ending of another non-canonical book, The Testament of Moses, since several early Church Fathers make that connection. If so, that means that Jude is not necessarily making any kind of ontological claim about the devil or demons, but is referring to a literary story with which his reader would have been familiar in order to make a point within the context of the book of Jude (rejection of false teachers and their spiritual pride). As such, it cannot be proof for an answer to Brian's question.
Grace and Peace,
From The Book of Jubilees
17:15. And it came to pass in the seventh week, in the first year thereof, in the first month in this jubilee, on the twelfth of this month, there were voices in heaven regarding Abraham, that he was faithful in all that He told him, and that he loved the Lord, and that in every affliction he was faithful.
16. And the prince Mastêmâ came and said before God, 'Behold, Abraham loves Isaac his son, and he delights in him above all things else; bid him offer him as a burnt-offering on the altar, and you will see if he will do this command, and you will know if he is faithful in everything in which you try him.
17. And the Lord knew that Abraham was faithful in all his afflictions; for He had tried him through his country and with famine, and had tried him with the wealth of kings, and had tried him again through his wife, when she was torn (from him), and with circumcision; and had tried him through Ishmael and Hagar, his maid-servant, when he sent them away.
18. And in everything in which He had tried him, he was found faithful, and his soul was not impatient, and he was not slow to act; for he was faithful and a lover of the Lord.
18:1 And God said to him, 'Abraham, Abraham'; and he said, Behold, (here) am I.'
2. And he said, Take your beloved son whom you love, (even) Isaac, and go unto the high country, and offer him on one of the mountains which I will point out unto you.'
3. And he rose early in the morning and saddled his ass, and took his two young men with him, and Isaac his son, and split the wood of the burnt offering, and he went to the place on the third day, and he saw the place afar off.
4. And he came to a well of water, and he said to his young men, Stay here here with the ass, and I and the lad shall go (yonder), and when we have worshipped we shall come again to you.'
5. And he took the wood of the burnt-offering and laid it on Isaac his son, and he took in his hand the fire and the knife, and they went both of them together to that place.
6. And Isaac said to his father, 'Father;' and he said, 'Here am I, my son.' And he said unto him, 'Behold the fire, and the knife, and the wood; but where is the sheep for the burnt-offering, father?'
7. And he said, 'God will provide for himself a sheep for a burnt-offering, my son.' And he drew near to the place of the mount of God.
8. And he built an altar, and he placed the wood on the altar, and bound Isaac his son, and placed him on the wood which was upon the altar, and stretched forth his hand to take the knife to slay Isaac his son.
9. And I stood before him, and before the prince Mastêmâ, and the Lord said, 'Bid him not to lay his hand on the lad, nor to do anything to him, for I have shown that he fears the Lord.'
10. And I called to him from heaven, and said unto him: 'Abraham, Abraham;' and he was terrified and said: 'Behold, (here) am I.'
11. I said unto him: 'Lay not your hand upon the lad, neither do anything to him; for now I have shown that you fear the Lord, and have not withheld your son, your first-born son, from me.'
12. And the prince Mastêmâ was put to shame; and Abraham lifted up his eyes and looked, and, behold a ram caught . . . by his horns, and Abraham went and took the ram and offered it for a burnt-offering instead of his son.
13. And Abraham called that place 'The Lord has seen', so that it is said in the mount the Lord has seen: that is Mount Sion.
14. And the Lord called Abraham by his name a second time from heaven, as he caused us to appear to speak to him in the name of the Lord.
15. And he said: 'By Myself have I sworn, says the Lord, Because you have done this thing, And have not withheld your son, your beloved son, from Me, That in blessing I will bless thee, And in multiplying I will multiply your seed As the stars of heaven, And as the sand which is on the seashore. And your seed shall inherit the cities of its enemies,
16. And in your seed shall all nations of the earth be blessed; Because you have obeyed My voice, And I have shown to all that you are faithful unto Me in all that I have said unto you: Go in peace.'