The trouble begins when affiliation is confused with identity. Identity is what I see when I look in the mirror. Affiliation is the state of attachment to a larger group. One can affiliate with a larger group without “identifying” with it, and conversely, one can identify with a particular type of Judaism without having any institutional affiliations. There are plenty of people who affiliate with Orthodox synagogues but would not define themselves as Orthodox Jews, and plenty of Jews who identify themselves as Reform without affiliating with any Reform institutions.
Unfortunately, though, we tend to assume that anyone who affiliates with a particular group conforms to the properties of the group as a whole. Consequently, there is pressure to break things down into smaller groupings — lest, heaven forbid, one be “identified” with the wrong group — or to insist that one defies categorization.
Elli Fischer, “Don’t Confuse ‘Identity’ And ‘Affiliation’”, The Jewish Week (25 April 2014), 20.