RE: What does the Bible say about the dead? - Part 1
Certainly, there are weird things that happen in life where you can feel "guided" spiritually by something unexplainable. Of course, the possibility exists it was just plain luck. But assuming it wasn't luck, assuming you were guided spiritually, I'm sure you must have been wondering if that was your grandfather's spirit guiding you.
One thing to keep in mind is that the devil and his angels know you very well. Constantly studying your habits, your weaknesses and can impersonate you with incredible accuracy. It's very possible if you were "guided" by your grandfather's spirit that it was a demon. Keep in mind, even the devil can impersonate Jesus or anyone.
Consider the following text. The Devil was able to impersonate Samuel and can impersonate an Angel of light. What this tells us is we can't trust our senses...we need to rely on Gods Word to not be deceived.
1 Samuel 28
11 The woman asked, “Who do you want me to bring up for you?”
Saul answered, “Bring up Samuel.”
12 And it happened—the woman saw Samuel and screamed. She said to Saul, “You tricked me! You are Saul.”
13 The king said to the woman, “Don’t be afraid! What do you see?”
The woman said, “I see a spirit coming up out of the ground.[b]”
14 Saul asked, “What does he look like?”
The woman answered, “He looks like an old man wearing a special robe.”
2 Corinthians 11:14
"...For Satan himself transforms himself into an angel of light."
No, it was the real Samuel. That's why she screamed.
https://enduringword.com/bible-commentary/1-samuel-28/
iv. Some believe that this was a genuine (but strange) appearance of Samuel. This is the best explanation because it is supported by the reaction of the medium, who got more than she bargained for. It is also supported by the truth of what Samuel said (and the text says that Samuel said it). Some may say that it is impossible for Samuel to reappear in some way, coming from the world beyond back to this world. But Moses and Elijah also came from the world beyond back to this world when they appeared with Jesus at the Transfiguration (Matthew 17:3).