I don’t know about other religions but being jewish really means you live somewhere on the line of ‘how jewish you are’. The level of jewocity you are is linear up to a point.
If you are, or consider yourself jewish you appear on the line somewhere.
Anybody to the left of you on the line (less religious) is by your standards not really jewish and anybody to the right of you on the line is crazy.
Once you get into the ultra orthodox/hassidic arena, the line forks out into many lines where groups can be
differentiated by how they wear they hats.
All of them are crazy and they think that nobody else is really jewish except them.