“The Spirit of the Lord is upon me, because he has anointed me to proclaim good news to the poor. He has sent me to proclaim liberty to the captives and recovering of sight to the blind, to set at liberty those who are oppressed, to proclaim the year of the Lord’s favor.” - Luke 4:18-19
One-third of Jesus’ ministry was casting out demons, and he affirms in Mark 16:17 that “these signs will accompany those who believe: in my name they will cast out demons.” Yes, unclean spirits can oppress the believer; in fact, deliverance is only for the believer. This does not mean you failed or are a bad person, it means that at some point in your life a door was opened allowing legal access for a spirit(s) to enter. Now for the good news… you can be free!