Question: I heard someone say that the spirit of Samuel that the witch of Endor called up at 1st Samuel 28:11-19 was of Satan not of God. What is your take on this?
Response: It is true that this woman was engaged in immoral, demonic, and even illegal activity (Saul had outlawed this terrible practice of consulting spirits). Consulting spirits, along with all forms of necromancy, is anti-God in the extreme (cf. Ex.22:18; Lev.19:26). It may be possible to claim that you "didn't know" you were worshiping another god when, to take an example, you put money above the God (you cannot worship God and "Mammon", so all greed is essentially idolatry: Col.3:5; cf. Eph.5:5). But when for spiritual direction you deliberately go to a source other than God (and which is clearly not of God), that is a direct insult to the Almighty. And there is no worse such insult than consulting demons.
All such "actual" necromancy (i.e., everything that is not pure fraud), is indeed connected with demons, and therefore with the devil, Satan. And it is clear from the context of 1st Samuel 28 that the woman in question (i.e., the "witch" of Endor) is either an outright tool of the devil (through one or more of his demons possessing her or at least controlling her), or an indirect one (earning a living by pretending to be able to "bring up the dead").
However, critical to your question is the fact that even demons in control of a person can no more "bring up the dead" than they can do anything that is ruled out by God. They can, however, make a "good show" of it, and the Hebrew word here, `obh, אוב, since it also means a wineskin bottle, may reflect either the sound (a hollow ghostly sound) of such a performance, as well as the fact that the demon is using the person as a "vessel". In any case, while this may be a case of real demon possession, it could never be a real "bringing up of the dead" - not, that is, without God's intervention.
And this is clearly Samuel - no demon would ever wish to have a likeness of Samuel say what this "spirit" says. Furthermore, the medium (or "witch"), upon seeing the real person of Samuel actually coming up from below the earth, is thrown into a complete state of shock, immediately recognizing that she has been deceived (and realizing in the bargain that her client must be king Saul). So this is clearly not a "normal" performance for her, but a completely abnormal one in that she actually is seeing a person from beyond the grave, something beyond her (or her demon's) capability of producing herself in fact (all previous such performances having been merely pretense).
No, I think there is no question but that God has here granted Saul's request, an awful and awfully misguided one – one that only serves 1) to show the depths to which Saul has fallen spiritually, and 2) to confirm that his end is near as a result of his apostasy, manifest by just such behavior as consulting the devil's agents instead of God (cf. Is.8:19). So the medium is the devil's agent, the demons who possess/control her normally are the devil's agents, Saul is following the devil's will rather than God's, but this spirit is actually sent by God to confound them all, a fact that seems evident by the godly message given, a message completely confirmed by events (something impossible for demons who despite their power can no more see the actual future than we can).
Please also see the following links:
Demon Possession (in SR #4)
The Demon Possessed Girl in Acts 16:16.
Witchcraft, Sorcery and Magic in the Bible.
Drugs and Witchcraft
Politics and Society
Hope this helps,
Yours in Jesus Christ,