What is a true fan

One thing that I kept wondering is how big of a star trek fan do you have to be for it to be considered a religious obsession. The reason I ask this is some people who say they are religious do not even go to church on Sunday and actually only go to service around the holidays. Some of these star trek fan have been to more conventions in year than some people who have been to church in year. I mean to be considered a star trek fan do you have to seen every episode like these people. Also do you have to like every single part of star trek to be considered a true fan? People who are religious have different sects that match up with their beliefs. I wonder if this true of star trek are there some fans that only like the first series and say rest horrible or are there some fan that only like next generation? If there are different sects of star trek fandom than I think it is a lot more similar to religion then I thought. I wish Icould have seen people in the video how did not like every part about star trek and only liked one series.