The problem with the Jews' god/God wasn't that he was referred to as the "only" God, but rather, that he was unique to them. To call the Romans of the First Century AD (and afterwards) "polytheists" is misleading. I prefer the term "pagan" insofar as it refers to an entire religious viewpoint.

Christianity was indeed considered a "cult" in the sense that it was a secret religion, but in that respect it was no different than the Greek Mystery-Religions that it was modelled after. The rites of Dionysus, or the Magna Mater, or Demeter and Kore, or Orpheus, or the great Eleusinian Mysteries, were very popular. The Mithraic mysteries became greater than all of the previous ones put together and, as you know, vied with Christianity for prominence. Most of these religions professed an ultimate unity of reality - I can quote you passages from the Poemander and Asclepius of the mysteries of Hermes Trismegistus if you like. They were, so to speak, monistic polytheists. There isn't much difference between that and monotheism proper.


Mormonism may not seem "odder or less odd" than Scientology to you, but it differs in key ways that I mentioned earlier. It has stories, myths, beliefs that draw on the power of traditional Christian beliefs and may add to them in unusual ways, but it still presents an emotionally powerful worldview. Scientologists tell no compelling tales and have an emotionally weak religion. The only interest has been from some unbalanced actors and people interested in participating in a tax dodge.