What do the Scriptures have to say about mediums (people who contact the dead, foretelling the future, etc)?
In Acts (16:16-18) a servant-girl, who made a lot of money for her master, had a “spirit of divination.” This phrase, “spirit of divination,” according to the Greek philosophers of the first century of the Common Era, was applied to ventriloquists. The idea forwarded was that a person would speak in the voice of another – i.e. a spirit from the underworld. In the Greek Old Testament (the Septuagint) the word “ventriloquists” is precisely the term used for “mediums” (Lev. 19:31; 20:6, 27; 1Sam. 28:7). The apostle Paul took for granted that this was nothing more than an “evil spirit” and in the name of Jesus Christ called for it to come out of the girl, which it did.
Other than warnings to either abandon or otherwise having nothing to do with this sort, both the Old and New Testaments do not reveal much at all about this dark art. Many today feel secure in discounting any and all supposed contact with the dead (or any other kind of fortune telling). Yet, the Scriptures are clear and experience demands that, while there certainly are counterfeits in this field, there are some who are especially sensitive to the things of the “spirit world.”
One who is especially sensitive to the voices (which we all hear, but most do not realize it) can easily, without a sense of good theology, mistake these voices for the spirits of those since passed. Also, these sensitive ones can mistake for God’s voice that which is actually the voice of the enemy. Concerning the former, the enemy hi-jacks the memory of beloved family members (for example) that have passed, the “medium” (the especially sensitive one) has contact with this spirit (the enemy), and both convey messages as though it is the soul of the beloved family member. Spirits are not bound by space and time. They are privy to “private conversations” between humans. And they not only heavily influence the unsuspecting mind, but they know the mind of the same. Incidentally, “hauntings” work according to this same principle. Both, the peaceful “loving” visitation by a family member and the violent invasion by “another,” are not human spirits roaming the earth (or haunting the chapel). They are, if you will, a counterfeit of the essence of residual energy left by those humans (the basis for this argument is based on every account of Jesus’ and His disciples’ interaction with demons/spirits). Concerning the latter, many well-intentioned people have communicated messages, which they thought were from God, but were actually the “other” voices of that “world” (based in both Old – see 1Kings 22:22-23 – and New Testament accounts of prophecy).
In the 1Samuel account listed above, the witch of Endor attempts to enchant the spirit of Samuel. By all accounts of the text – including her reaction to the apparition, the conversation between Saul and the apparition, and the very words of the apparition itself (VS 16), etc – this was not actually Samuel which was conjured. The Acts account speaks to the ability to foresee the future. The girl was not gifted by God for this and, therefore, had a counterfeit (called, “a spirit of divination”). It should be noted that, though it was counterfeit, it told the truth about who Paul and his traveling companions were. But not being from God, it was a point of confusion, contention, and agitation and, therefore, called out by Paul.
A logical consideration should be, here, made concerning the spirits of the dead: Those who claim to believe in the spirits of the dead, but deny the existence of God are self-contradicting. How does one not believe in He who is pure spirit, but yet believe in those which are lesser spirit? Further still, if there is no “God” (First Source, First Cause, Uncreated Creator), then there are no spirits (because they are immaterial, and therefore not of the material evolution, but must come from “without” the material order – where “God” would be if He existed). Likewise, if “God” does exist, then what kind of a “God” would He be if He simply let spirits roam the earth (which is completely illogical since they are not bound by space and time)? Furthermore, if “God” does exist, then His Word is the first principle concerning His existence, and it plainly states that the souls of the living are exclusively in one of two places after death; which of the two depends on what one does with Jesus Christ (or not).