This is my idea on what ghosts are, i wrote this before.
Introduction
The word ghost is the human term used for a spirit or supernatural energy force that once belonged to a living person, who has died and their spirit has passed on. The term ghost is defined as the spirit of someone who has died but cannot, for some reason, reach the next realm where spirits after death dwell. This is the basic idea held by most people of what a ghost is.
In our world ghosts are real, they exist, but not in the sense that most people think they do. To define what a real ghost is we will have to look at ghosts, not as beings, but as a form of manipulation, an action taken by something else.
Ghost is a demonic activity that occurs to some people in order to cause fear and deception. The demonic seeks only to steal, kill and destroy [John 10:10]. Remember that demons cannot possess followers of Christ, but they can oppress. For a demon to carry out possession they need to find a method to enter their victim. Doorways such as Satanism, witchcraft and primarily fear are the entryways for demonic possession. The ghost activity is used by demons in many cases as a method to strike unnatural fear into an individual, therefore opening the door for possession.
Types of ghosts experienced
Spirit of Deceased: Many people who have claimed to have seen a ghost say they recognise the spirit. People have seen ghosts of relatives who are deceased and claim to have had visitations and conversations with all types of spirits who once belonged to a living person.
Séances are an activity carried out in order to make contact with a spirit of a dead person. Séances nowadays are often carried out by families or groups of people who have recently lost a loved one. In many cases they wish to make a last contact with the person in order to express their sorrow and say goodbye. In some cases, these of course can be fake, in others however, they can be real.
Banshee: This is a type of ghost written about in old Scottish and Irish folk law. It is apparently the spirit of a young woman who wails in forests and swamps. Apparently, on hearing her wail, death will follow that person. They have been known to tap windows in order to entice people to open and hear the wail.
Poltergeists: Poltergeist activity is the extreme case of a spirit seeking to strike fear. Many individuals who have come out of a poltergeist scene have not been physically harmed. But many have been mentally and spiritually. The victims are often young girls. The situation is usually when a poltergeist, the type of spirit, causes objects to violently crash around the room. This results in furniture and other objects to be floating by themselves around the room.
Imprints: These are apparently spirits who are trapped in a certain location because memories were imprinted in that area. This is caused by a series of emotion events, like violence, or stress. The imprint apparently just plays through like a film over and over until it finally fades out of existence.
Wraith: A legendary ghost that is supposed to bring misfortune because of the death of a person. They are linked to death in someway.
Doppelganger: This ghost is supposed to be a copy of a person who is alive. It apparently appears to people in physical form. If the person sees a doppelganger that is a copy of themselves they are supposed to die soon afterward.
Guardians: These ghosts are meant to appear to the living to warn them of danger that is on the way, or to guide them through situations. They are apparently meant to be loved ones who died and have returned to help their family.
What are ghosts in reality?
Ghosts as we understand them do not exist. There is biblical evidence to support this.
Just as a man is destined to die once, and after that to face judgment
[Hebrews 9:27]
The bible teaches us that after death we either face Heaven or Hell, there is no middle ground. When people die, they do not wander the earth in search to complete something that is uncompleted, they go to judgment, and await the resurrection and their fate being Heaven or Hell.
So, knowing that this is true, what are ghosts?
Well, there are a two possibilities, and both are true. The first is a figment of the mind. Many people who have claimed to see ghosts have later realised that it was either seeing something normal, only in a different atmosphere, or a state of mind. Sometimes, for example, at night or in low lit atmosphere we can imagine things. We may be tired or drowsy, and our eyes are not accustomed to the darkness, so we imagine we can see things. This can explain many strange ghost like things people have seen. They see it, and the next day they realise it was a coat or their cat. Also, as a state of mind, people can be under emotional strain and actually believe they are seeing ghosts. Both of these are possible.
However, there are situations were both of these can be ruled out. For example, when a person is not in any emotional strain and they are not in a tired state. Some people have had multiple visits of the same spirit like being.
There are black arts such as spiritism and necromancy which mediums, sorcerers and witches have used in order to call upon a spirit. In some cases again, these can be fake. But for true spirit summoners it is not. Spirits have and will actually appear, in a manifested state before these people.
These spirits that actually appear are none other than demons.
Read 1 Samuel 28
In this passage of the bible we see how King Saul attempted to contact the prophet Samuel. Saul had disobeyed Gods command of not visited mediums or attempting to conjure up spirits. In verse 12, when the woman saw that the spirit of Samuel was actually coming up she was terrified and cried out loud. This medium had been used to seeing her familiar spirit, but was actually a demon decieving her. In this case God probably allowed Samuel to return to show that God has more power than demons. The medium herself was scared!
Satan has used ghost for another reason since the dawn of time, deception. The bible says that after death comes judgement; heaven or hell. Satan has deceived from the time he deceived a third of angels all the way and continuing today. He will try anything to force people to believe in something other than what the bible teaches. Satan knows he is doomed as he knows the bible speaks the truth. Satan knows his time is short and there is nothing he can do. The only possible action he can take to feel better is to know that he can drag down as many people as he can along with him to reek his revenge against God. God does not want mankind to suffer, but it happens. He does not want men to be thrown to eternal doom, but it will happen.
Over the centuries Satan has tried many different methods of deception to make the bibles truth seem false. One more recent method is the theory on evolution. In this scenario Satan has ruled God out altogether, claiming that the world and creation was formed in an entirely different and absurd manner. Ghost is a method still used today, but it has been used in the past, as I said, almost since the dawn of time. In the time of Saul the belief on Spirits was rife. King Saul himself in 1 Samuel 28 attempts to contact the spirit of the dead Prophet Samuel through a medium. This action of Saul proves that he himself had given up on God and had given up his belief in the true events that occur after death. Satan fooled the disciples with ghost. In Matthew 14:22 when Jesus is walking on water out to meet his disciples they become frightened and think that he is a ghost. After the resurrection when Jesus appears before all of his disciples he knows their thoughts and their false views that he may be a ghost. Jesus proves that he is not a ghost and that ghosts do not exist. Luke 24:36
Jesus himself was suddenly among them. He said, Peace be with you. But the whole group was terribly frightened, thinking they were seeing a ghost! Why are you frightened? he asked. Why do you doubt who I am? Look at my hands. Look at my feet. You can see it is really me. Touch me and make sure that I am not a ghost, because ghosts do not have bodies as you see that I do! Jesus knew the perception that Satan had caused among people at this time. To believe in ghosts is to believe that after death there is no Judgement. The bible teaches it is judgement after death, but to become a ghost means to avoid judgement, and this is not so. Satan was using this as a method of deception and a way of casting doubt into peoples minds. Jesus proved that after death it is not ghost but it is judgement. In the case of a Christian a new body. Coming back to the story of Saul and the Medium. The medium called for the spirit of Samuel to appear, and he did. The witch was frightened by this. She had expected the spirit (demons) to come and tell her a message, but instead the powers of the demonic were overthrown and God actually sent Samuel to prove that ghosts did not exist and that it was only the demonic fooling mankind.
As I have said, Satan and the demonic use ghost activity to strike fear into people and to sway people from the truth that after death it is judgement.
2 Thessalonians 2:9 The coming of the lawless one will be in accordance with the work of Satan displayed in all kinds of counterfeit miracles, signs and wonders
It is in this way many have been deceived. Joseph Smith, founder of the Mormon religion, claims to have been told to do so by an angel of God. I believe that he was fooled into doing this. The Mormons religion caused a great deal of confusion, the bible tells us we should always test spirits to see if they are of God.