Scripture contains many references to angels and demons. Demons are not an

abstract sense of evil but beings of intelligence and intention.
Intelligent beings can choose between good and evil. If there are good
spirits then there can also be evil spirits. Both scripture and human
experience attest to this.

Jesus’ first act in the Gospel of Mark is to cast out an unclean spirit.
Delivering people from evil spirits was an essential part of Jesus’
ministry along with teaching and healing the sick. The Gospel writers
distinguish very clearly between physical healing and driving out demons.
Jesus’ chief title is ‘Savior’, and He rescues us from real danger.

There are different levels of demonic disturbance and different levels of
intervention. Temptation is a disturbance directed against everyone.
Extraordinary disturbances include demonic possession, diabolical
oppression, and diabolic infestation. All Christians can offer prayers of
deliverance but only priests and bishops can perform exorcisms for demonic
possession.