The Scientology movement and its treatment of homosexuality.
Scientology is busy rewriting its history to appeal to a new generation, which almost makes it a Proper Religion, but its murky past is there to read (and ignore?) in L. Ron Hubbard’s questionable tome Dianetics.
Gay Scientologists have since embarked on the work of reinterpretation. This is how you can tell it has become a Proper Religion: a host of followers pick and choose, then ignore the things they don’t think should apply to them.