What does the Bible say about demonic possession?

In Mark 5, we encounter a man possessed by a legion of demons, representing both the reality of spiritual darkness and the hope found in Christ. This passage portrays the individual's condition as one of desperation and utter hopelessness, living in a graveyard amongst the dead. The scriptures reveal that demons are real and can exert influence over individuals, leading them away from the simplicity found in Christ. However, it is crucial to understand that all authority over the spiritual realm belongs to Jesus, who has the power to cast out demons and bring freedom to those who are captives of sin and deception.