I believe that's part of it, but Paul was writing generally about sin in his daily life.
Question: If a pastor was trying to land a job at a church and they told the hiring body that they were controlled by a demon that was causing him/her to do things he/she didn't want to do, would he or she get the job?
And if you had a daughter who, having her date come to the house to pick her up, he arrives and steps inside for a quick intro and take your daughter to dinner, or whatever. If he told you that he was filled with a demon that wouldn't let him do what was right and only what was wrong, would you let your daughter go with him?
Edit - Sorry, this is poorly written.