I think it mostly has to do with the 9th house cusp and any planets in the 9th house. A fixed Sign ruling the 9th house cusp could make someone really stubborn about there opinions on religion. I think maybe Saturn in the 9th house would be somewhat fixed on there view on religion. I'm not sure if that would make them want to argue there views, but maybe make them more likely to be close minded and not willing to see any other way. I'm not an expert but, if I had to make a guess thats what I would look for.
I would like to hear some more answers from some more educated astrologers.