How can a Christian have a demon?

QUESTION?

How can a Christian have a demon?

ANSWER!

There are three main reasons why someone who confesses the Name of Jesus may have a demon.  Fist, Christians can be slothful in their practice of the faith or vulnerable to demons through unrepentant and unconfessed sin.  Christ cannot fully protect even His followers who do not invoke His protection consciously.  Second, the Lord allows Christians to suffer in this way to "test" or "prove" them in the fires of adversity.  The devil is most effective in offering that kind of spiritual testing, and sometimes it comes as internal obsessions rather than merely external forms of persecution.  Third, "God wishes to give us a true knowledge and understanding of ourselves" and show us how impossible it is to advance in His service without the aid of His grace.

Some have wondered how it is possible for the devil to inhabit a body which St. Paul says is the "temple of the Holy Spirit."  It would seem that God and Belial cannot exist in the same place at the same time.  But an unclean spirit may enter and inhabit a body in the same way that a sin may enter and stain a soul: by the human will, which gives permission for its entrance.  Or to use another analogy: a demon may enter a body in the same way a Satanist may enter a church building; either through a deliberate wicked action or a free invitation.  The mere fact of God's Presence in a place does not prohibit the action and activity of human or spiritual evil even though a place may be sacred.

By Rev. Thomas J. Euteneuer "Exorcism and The Church Militant" pg 108.