Letter From a Roman Jail: Ephesians
Demonic influence is a human problem.
There are real spiritual beings that are evil. They are hostile to all that God has made, especially human beings. They are doomed, but can still affect the world and human beings.
The doom you deserved was taken on by Jesus, and the destiny He deserved was offered to you - by grace alone, received by faith alone, in Jesus alone.
The Lord has provided you His armour, and empowered you and called you, to stand in spiritual battle.
You both stand, and advance, on your knees, in prayer, in the Spirit.