I just read the Animism article. It states that Christianity specifically teaches against the existence of ghosts (spirits of dead people) in the world, and that dead people cannot communicate with the living and vice versa. What about the passage in I Samuel 28 with Saul and the witch of Endor? She calls up Samuel’s spirit to communicate with Saul.
The incidence in 1 Samuel 28 is one of two exceptions to the “no crossing over” boundaries in scripture, both highly supernatural miracles. The witch of Endor had no power to truly conjure up the spirits of dead people; that’s why she screamed in terror when Samuel actually appeared. It was God at work, not the witch or even the departed prophet responding to the summons. Samuel gave the word of the Lord to Saul, and his prophecy was fulfilled shortly thereafter.
The other miracle was when Moses and Elijah appeared along with a transfigured Christ to Peter, James and John (Matt. 17). The disciples did not summon the spirits of these dead saints; they were sent by the Father (probably to encourage the Lord Jesus).
The fact that there are two biblical exceptions, both of which required divine intervention to send departed spirits into this world, does not affect the truth that there is a “great gulf fixed” between the living and the dead (Luke 16:26). That’s the point of miracles: they are God-powered exceptions.
Hope this helps!