Summary: How do we go to battle without becoming demon chasers? There are two extremes to avoid. Some people tend to blame every adversity on the devil, always assuming, "It's a demon!" They're impressed by the heaviness and the oppression. They know all the spiri
Demons are known to operate in both the soul and the body.
There is no Biblical evidence that I am aware of where demons are known to specifically operate within a man's spirit. Every time we see a demonic spirit at work in the life of a person, it is either through the soul (mind) or the physical body. In Matthew 17:15,18, we find an example where a young boy was mentally ill because of a demonic spirit:
"Lord, have mercy on my son: for he is lunatic, and sore vexed: for ofttimes he falleth into the fire, and oft into the water. And Jesus rebuked the devil; and he departed out of him: and the child was cured from that very hour."
The term lunatic here in the NT Greek translates to the word seleniazomai, which means moonstruck or crazy. To be moonstruck literally means mentally unbalanced, or mentally ill. Clearly the boy was affected mentally by this evil spirit.
People are also known to be physically affected by demonic spirits. In Luke 13:11, we are shown of a perfectly sane woman who was physically bound by a spirit of infirmity:
"And, behold, there was a woman which had a spirit of infirmity eighteen years, and was bowed together, and could in no wise lift up herself."
It is not uncommon for people to be tormented and harassed with fear and other mental torment, such as the case 1 Samuel 16:14, where King Saul received an evil spirit:
"But the Spirit of the LORD departed from Saul, and an evil spirit from the LORD troubled him."
When we trace the word troubled here back to the OT Hebrew, it gives us the word baath, which means to terrify, trouble or overwhelm a person. It is not uncommon for people to be mentally harassed by evil spirits in this manner.