1Sa 28:13 And the king said unto her, Be not afraid: for what sawest thou? And the woman said unto Saul, I saw gods ascending out of the earth.
She saw gods--pleural--ascending out of the earth.
The NRSV translates
elohim here as "a divine being", which I think is a pretty good way of putting it. Yes,
elohim is the plural construction of the word, but grammatical context is essential. It is also essential that we understand the different ways in which language operates. We translate
elohim as "gods" or "God" (depending on grammar and context), but that doesn't always mean the concept--as the ancients understood it--was identical to our concept of gods. Etymologically the word is related to "mighty", the most literal translation of
elohim is "mighty ones". The word is used in reference to mere mortals, for example, in Psalm 82.
The medium believed she saw something so incredible that she describes it as seeing "gods" ascend from out of the earth. Does she believe this is a "god" in the purely theistic sense, a powerful being of some kind, a great spirit, etc? That's not possible to know I don't think. But that's not really the point of the text either: the point is the Saul went to see a medium, he desired to see Samuel. There is no reason to believe the medium actually had the power to call forth the dead, nor is there any reason to believe that she called forth a demon imitating Samuel. The text says two things: that the medium became deeply frightened, and instantly knew the stranger visiting her was King Saul; second that this was Samuel. That's what the text
says.
If you believe that this is Samuel, who is now in heaven with God and as such is still an old man covered in a mantel, but is coming up from the earth, instead of descending from above, along with "others"----maybe it's your theology that needs to change.
Samuel would have been in She'ol, which is always described as "below". It was the Hebrew view that She'ol was the common destination of the dead, by the time of Jesus She'ol was understood to have two parts: the place of the righteous dead known as Paradise and the place of the wicked dead known as Gehenna.
Describing Samuel as ascending from the earth is totally in keeping with biblical and traditional Christian teaching on this matter. The Harrowing of Hell did not happen until Christ plundered She'ol when He descended into Hades and set captives free.
"The "bible" is not calling this apparition Samuel, the witch and Saul are being quoted as to what they saw and believed.
The Bible specifically says it is Samuel. Whatever hoops you want to jump through in order to avoid that is up to you.
-CryptoLutheran