Is my friend possessed by spirits?

I'm a bit concerned that a friend of mine might need an exorcism. He's a really nice guy and we've been friends for a long time and certainly would not want to say anything that might alarm him or make him think he's evil because he's certainly not but I worry that he might have opened the door to a demonic realm by reading satanic literature. He read this book one time and now says he sometimes hears his name called when nobody's calling him and now has developed a fear of churches and the bible. He even claims to have bolted out of a church in fear. The unexplained fear of churches is a classic sign of possession which is what has me quite concerned. I know most "possessed" people do not commit violent acts and are not necessarily evil people, the demons just kind of control the person in subtle ways and mess up their lives and the lives of those around them. He just seems to have changed very drastically. Obviously, I acknowledge that this may be unlikely and he could be just saying it like this for attention and stuff like the hearing your name called thing can be normal, in fact, that's happened to me a number of times and happened a good bit back when I was a teenager so that could be just a simple trick of the mind and he could be just saying he's scared of churches to make people think he's possessed. He hasn't levitated or anything as far as I know, but one could be possessed without doing anything obviously supernatural right? I just don't get why someone would be scared of a church unless there was something supernatural going on, it isn't like churches are a scary thing. He's also a very devout atheist in terms of his philosophy if that makes any difference. He doesn't worship the devil or anything, he just read the book out of interest but I could see how a demon would be very drawn to somebody who even layed eyes on such a book. I mean who the hell (pardon the pun) reads the fucking satanic bible unless they want to be possessed?