A common complaint among Christians about the idea of human spirits, ghosts, is that when a person dies they believe that since the Bible says that we die once and then face judgment (Hebrew 9:27) and that the dead know nothing (Ecclesiastes 9:5) they believe that it is impossible for a human spirit to return to the world of the living. They therefore conclude all occurrences of human spirits to be demonic spirits, or possibly angelic spirits in some cases, in disguise.
The central problem with this interpretation of scripture is that the actual assumption is not a Biblical one. The bible is already clear that even some spirits from Heaven and Hell alike come to earth. God sends his angels and even Satan appears to tempt Christ. People drawing this conclusion are assuming that humans are restricted in a way that the angels are not. Further they are deliberately twisting the interpretation of other verses that directly contradict their view point. The most prominent place this interpretation fails is the account of the Witch of Endor (I Samuel 28:3-25). In this account King Saul goes to the Witch of Endor to seek advice from the spirit of Samuel. What’s important here is that the scripture states clearly that the spirit of Samuel appears. It does not say a spirit in the shape of Samuel or a spirit claiming to be Samuel it says it was Samuel. The behavior of Samuel’s spirit is also completely contradictory to the idea it was a spirit. He condemns the Witch and Saul for their actions where a demon seeks to encourage sin and wickedness (John 10:10). The argument could be made that the spirit was a holy angel but why would a holy angel deceive Saul instead of just appearing as their true self? By interpreting Samuel in this verse as anything other then Samuel people are interpreting scripture to meet their own already held beliefs instead of basing their beliefs no scripture.
Endor is not the only example of human’s returned to serve God’s purpose either. Moses and Elijah appeared with Jesus during the Transfiguration (Matthew 17:3) again the bible says human souls returned to Earth when God allowed it. These two examples seem to directly conflict with the traditional interpretation that humans can never come back.
Another possibility exists. That God in his mercy allows those who have already faced judgment and been found worthy to return. Not those condemned to Hell, not even those in some kind of waiting room for Heaven but that some people are permitted by God to return for a reason. These spirits would not have special knowledge, which is why we are told the dead know nothing (Ecclesiastes 9:5) but are here for some purpose either to do God’s will (like with Samuel) or to work out some personal issue they need to work on to find peace. In fact the Bible says we are surrounded by a great cloud of the witnesses (Hebrews 12:1). Who are these witnesses if not those who have gone before us into Paradise? This also resolves a fundamental conflict the traditional interpretation has with one of the most common types of spiritual experience.
It is extremely common for people to describe being visited by a loved one who has passed away. Sometimes it’s the feeling of their presence, or some minor physical effect like a smell or a flickering light, some times they actually see the person. These are not haunting in the sense you see in movies or on television it is a single event or a series of sporadic ones almost always occurring with in the first year or two after the person dies or when the person is under great stress. People who report these experiences usually report feelings of peace and a certainty that their loved one is all right. No prophetic acts, no displays of demonic power just an action that helps a person who is suffering find peace. Demons do not seek to bring people peace they seek death and destruction (John 10:10) they do not show up one single time to help a person in pain get on with their lives and never return. Instead of judging this as wicked because of a preconceived notion it should be judged by the standards laid out in Scripture. The Bible says that a tree can be known by its fruit (Matthew 7:16) and to test a spirit (1 John 4:1). When events like this ease pain and bring peace their fruit is good and when they honor God and renew a person’s faith the spirit passes the test. This is not to say all paranormal phenomenon is God simply that the knee jerk reaction of condemning the paranormal as Satanic in origin is not a Biblical response. Study the situation, test the spirit, and look at the fruits of that experience rather then judging it based on what the viewer assumes is true.
Also none of this is to say that people should seek to reach out looking for spirits of the dead. The Bible is clear that the practice of necromancy is against God's law (Leviticus 19:31, Deuteronomy 18:11). This is dealing with the issue of a spirit that arrives on its own without being sought. Certainly one should not take a seeming paranormal event at face value the instead should test what happens both against their rational belief and as Scripture indicates.