I have been a dues paying member of a Trotskyist party and believe me that before I would go back to that idiotic mumbo jumbo, I _will_ walk into a Quaker congregation or check out the Unitarians. This is not a reflection on Trotsky but on the demented behavior of such political parties in the U.S. I mean you want to talk about absurd ritual and misguided beliefs all rendered in the most obsolete formulaic language imaginable, you can't really do better than such parties.
[WS:] Amen ;)
As to Chuck0 comment why people do not build a community themselves - community is something that grows organically around you. If you try to design it, you get a corporation or a pathetic Trot grouplet. At least the former serve some rational purpose, even if that purpose is mere greed. The latter is basically no more than psychotic emotional jerking off.
Churches cultivate organic communities because they speak to everyday concerns of most people - fear, sadness, joy, love, alienation, failure, support, reciprocity, safety, loneliness, despair. Those concern mean something to people, and mere acknowledgement of them by a community of people - like in a church - provide personal and emotional support that most people value.
And what do most lefty groups have to offer? Harangues, lecturing, guilt trips, self-depreciation aka self-criticism, angry accusations, blame games, incomprehensible mumbo jumbo, narcissistic personality cults.... These are immediate turn offs for almost everyone but a few with affective disorders. No wonder that people prefer churches - it is a much more emotionally soothing environment.
Wojtek