A few days ago my priest was talking about dark spirits. He taught us about demons, about how they're trying to bring us down and keep us away from the Lord, and shared a few stories about people who got possessed and how they had to get treated by an exorcist. He told us about some tape on youtube that shows a missing teen named John Kirk. I watched it and now I can't stop thinking about it and wondering how can one prevent that sort of situation.
You can find the tape on youtube under-