The ancient world, including the Jews, believed in the influence of demons. There were different beliefs about their origin. Some believed that they existed even from the time of creation. Another belief was that they were the souls of the wicked people who have died continuing their malicious deeds entering others’ bodies. The demon possessed person spoke as demons. The demons caused physical and mental disorders in the possessed person. Such a person possessed by the “unclean spirit” was “unclean” and ritually impure.
The gospels present demon-possession as a common phenomenon. They use “Unclean spirit” and “Demon” interchangeably to refer to supernatural beings who could enter the life of humans and take control of them (Mt 12:43-45, Mk 5:2-5). Before the development of scientific clarity on the reasons for diseases, people attributed the cause of mental disabilities to the evil spirits. The belief was that the demons were present at tombs and desert places. They caused the epilepsy (Mk 9:17-27), mental disorder (Mk 5:1-5) and physical disabilities like dumbness (Mt 9:32-33) and blindness (Mt 12:22). When the sick persons were convinced that the demons had possessed them, they would produce symptoms of the demon possessed. For such people, the cure could happen only when they were convinced that the demon had left them.
The Catholic teaching is that Satan (devil) and demons were angles created by God. But they became evil by their wrongdoing (CCC 391). These created spirits had rejected God and his reign out of their free choice (CCC 392). The sins of angels were unforgivable, and they had no chance for repentance like there is no chance of repentance for humans after death (CCC 393). However, the influence of Satan and demons will have an end with the second coming of Jesus Christ.
DEMONS’ APPOINTED TIME
God has allowed the evil spirits to torment the humans only until the last judgement (Enoch 16:1, Jubilees 10:7–10). The demons knew that the appointed time had not arrived. So, they considered they continue tormenting the humans. However, Jesus, who had power over the evil spirits, expelled the demons from the demoniacs and liberated them from their bondage.
Mental illness cannot be attributed to the demons. However, the demons can influence us to do the evil against God and our fellow humans. Through baptism, we have renounced the devil and accepted Jesus into our lives. Like Jesus, let us gain strength from Jesus when we have trials in our lives.