The content of an obsession may be more or less fearful depending upon how it brushes up against what you value and/or what you fear.
The level of fear you have of the content will result in a graduated experience of anxiety; how intensely and frequently you feel the anxiety.
The intensity and frequency of the anxiety that you experience will result in the necessity of performing a compulsion. Mental compulsions are no different than physical compulsions.
How much you identify with emotions and thoughts and therefore how you experience them in your mind and body will be determined with the ownership that you take of the thoughts, emotions, and physical sensations.
How you relate to the thoughts, emotions, and physical sensations will always have a direct result on the intensity and duration of the OCD loop. When you are able to be the impartial observer vs. being and owning the thoughts and emotions then they become something completely different;difficult for the intellectual/logical brain to comprehend.
The observer seeks to find no meaning in the thoughts, emotions and physical sensations.
The observer says, 'I'm observing thought X or emotion Y, now what was I doing before I noticed?' and 'Oh, there's another thought and another emotion, now what was I doing before I noticed?'
How do you get to a place where you can view thought and emotion as an observer? By practicing mindfulness. I'd recommend the Headspace app as a wonderful way to get started or visit their website www.headspace.com.