When Jesus appeared in the resurrected body, he was mistaken for a ghost and even said that ghosts don’t have flesh and bones (Lk. 24:39). The prophet Samuel prophesied from the grave (Sir. 46:20). Also, in the story of the Rich Man and Lazarus (Lk. 16:19-31), it’s implied that the dead can communicate with the living in verse 25. And even stranger is the possible separation of the spirit from the living body or bilocation in the story of Philip baptizing the Ethiopian in Acts 8:39: “When they came up out of the water, the Spirit of the Lord suddenly took Philip away, and the eunuch did not see him again . . .”
Accordingly, the Church believes that ghosts, or spirits, do exist. There are times when spirits appear to our benefit, but we are warned against attempting to contact spirits. We should be extremely cautious and guarded simply because Satan could be attempting to deceive us.
But what are they?
“Ghost” is another word for “spirit” (it comes from the German word Geist, which means “spirit”). There are three kinds of spirits: (1) the human spirit which combined with a human body make up a human being; (2) a spirit that that has no body, such as that of an angel or devil; and (3) the infinite Spirit—God–of whom the Third Person is the Holy Spirit or “Holy Ghost.”
When someone asks whether ghosts exist, he usually has in mind the first kind, a human spirit, but apart from one’s body. Hence Servant of God John Hardon defined “ghost” as a disembodied spirit. Christianity believes that God may, and sometimes does, permit a departed soul to appear in some visible form to people on earth. Allowing for legend and illusion, there is enough authentic evidence, for example in the lives of the saints, to indicate that such apparitions occur. Their purpose may be to teach or warn, or request some favor of the living (Fr. John A. Hardon, S.J., Modern Catholic Dictionary (Garden City, NY: Doubleday, 1980, p. 229).
The last sentence of Fr. Hardon’s definition implicitly gives the Church’s teaching on ghosts. Appearances of ghosts are understood with regard to our salvation. Ghosts can come to us for good, but we must not attempt to conjure or control spirits. The Church teaches that “spiritism”–seeking recourse or power from ghosts–is contrary to the virtue of religion (i.e., the Commandment “You shall have no other gods before Me”):
“All forms of divination are to be rejected: recourse to Satan or demons, conjuring up the dead or other practices falsely supposed to ‘unveil’ the future…
“All practices of magic or sorcery, by which one attempts to tame occult powers, so as to place them at one’s service and have a supernatural power over others–even if this were for the sake of restoring their health–are gravely contrary to the virtue of religion. These practices are even more to be condemned when accompanied by the intention of harming someone, or when they have recourse to the intervention of demons. Wearing charms is also reprehensible. Spiritism often implies divination or magical practices; the Church for her part warns the faithful against it. Recourse to so-called traditional cures does not justify either the invocation of evil powers or the exploitation of another’s credulity” (Catechism of the Catholic Church, nos. 2116-17, original emphasis).
“Ghosts are the spirits, or souls, of human beings whose bodies have died. They may hover around the earth “haunting” material places, usually houses. There seem to be four possible reasons for this:
1. They don’t yet realize they are dead.
2. They were so attached to their material places or possessions that they can’t detach themselves from them and leave.
3. They are working out some purification, penance, or purgatory, some remedial education or ‘reform school.’
4. They are consoling their loved ones who have been bereaved.
“Angels, in contrast, did not have human bodies in the first place and never will. Ghosts once had human bodies and will receive new resurrection bodies in heaven if they go there.”
Apparently, according to Dr. Kreeft, C.S. Lewis once claimed to have seen a ghost of his wife.