I found myself discussing whether ghosts were possible from a Christian POV. Most of our discussion revolved around the phrase, “To be absent from the body is to be present with the Lord” and Christ’s words to the repentant thief, “Today, you will be with me in Paradise.”
I personally think that ghosts as restless human souls are prohibited by biblical text. While the disciples thought they were seeing a ghost at first when they saw Jesus walking on water, it was Jesus after all and not a spirit. And while King Saul thought he was talking to the ghost of the prophet Samuel through the Witch of Endor, it was an evil spirit and not Samuel at all.
If the souls of saints immediately enter Paradise, it follows that the souls of damned humans immediately enter Hell. Or perhaps we close our eyes in death only to open them up before the Judgment Seat of Christ to be parted on the left and the right.
Whatever the case, ghosts as human souls seems prohibited. More likely, the Bible seems to indicate that they are the damned spirits of fallen angels.
Another possibility that would not contradict Scripture could be that ghosts are temporal echoes. A lot of ghost stories involve ghosts that simply repeat a pattern each night, going down the same path, appearing in the same window. In the case of these hauntings, maybe a soul’s echo is preserved. In this respect, the ghost would be something like a picture or recording of a person, but really not the person itself except in a superficial appearance as such.
Jonathan Edwards, author of the Pilgrim’s Progress, wrote some on this:
I wonder if anyone else has some thoughts on ghosts from a Christian POV?
— Sirius Knott