He didn't use the term "demon possession" because he didn't like the way it sounded, but his teaching on whatever he called it still amounted to the same thing, "demon possession", as we see described in the bible with unbelievers but not believers. So he was not just talking about a believer being outwardly influenced by demons, he was talking about them actually having demons inside them, hence why there was so much screaming in his church services as the demons were supposedly being cast out.