Distinguishing the Difference Between Oppression, Obsession,
and Possessiongenerally speaking, an "unclean spirit" indicates the
nature of an evil spirit—that it is a fallen eternal spirit
being. Specifically speaking, however, an unclean spirit
refers to its type or kind, as in the case of the madman
of Gadara.
Another key element to notice in Mark chapter 5 is
that when the evil spirits could no longer oppress,
embody, or possess this man, as a second choice, they
sought embodiment in animals—these demons asked
Jesus for permission to go into the swine (Mark 5:12).
As eternal evil personalities, if evil spirits do
embody man, they make man what they are. In other
words, a person will take on the character and
personality of the type or kind of evil spirit that is
influencing him.
I said that in its broadest sense the term "unclean
spirit" refers to spirits of a fallen nature. But used in a
specific sense as in Mark 5, the term "unclean spirit"
refers to the type or kind of evil spirit it is: Referring to
its kind, Jesus said, "For he [Jesus] said unto him,
Come out of the man, THOU UNCLEAN SPIRIT" (Mark
5:8).
We know that this wasn't the spirit's name, because
in verse 9, Jesus asked its name: “... What is thy
name? ..." The evil spirit replied, "... My name is
Legion ..." (Mark 5:9).
It's obvious that this man took on the characteristics
of the unclean spirit. The unclean spirit caused the man
to tear off his clothes, to wander around naked, and to
cut himself with stones (Mark 5:5; Luke 8:27).
It's likely this evil spirit was manifested through
this man in connection with the sexual appetite of man.