The Christian and Demons

How can a christian, with the holy spirit dwelling in them, have a demon? Is this what hollywood describes as possession?

Most Christians are sensitive enough to not get their theology from Hollywood. Yet in this particular area, when the subject of demons is mentioned, most immediately think of movies and television portrayals of demons and hollywood style possession. This has had a cencorship effect on what was a powerful ministry of Jesus Christ. Any, why it has become one of the most controversial issues in the Body of Christ today. The uncertainty surrounding this issue creates an obstacle to the greater move of the Holy Spirit taking place on earth.