What are the "mystery cults" of the late Roman Empire?

Dunno, it's a mystery.

Religious organizations that required demonstration of merit, knowledge, and the gaining of rank to gain access to higher spiritual knowledge and benefits.

Freemasonry is a modern mystery religion, although there were thousands ranging from the imported-yet-unrelated Mithraism to the absolutely ancient Eleusian mysteries.

>>2700322
Was it true that they were overtaking the traditional paganism in Rome?

>>2700335
"Traditional paganism" in a Greco-Roman sense is kind of an anarchism. You had the phenomena for many centuries of Westerners adopting eastern gods into the Pantheon while easterners never adopted western gods into their pantheon. Ultimately you could say though that many people adopted some sort of philosophy or mystery religion instead of exclusively practicing the state paganism.

>>2700368
Was the public paganism more just a form of ritualism (like Shinto rituals) as opposed to a religion that one had a personal connection to?

Scientology.

>>2700387

Oh, or Freemasonry.

>>2700116
Is that a reference to crash course mythology

>>2700380
Pretty much.

>>2700486
a lot of podcasts about the late Roman Empire refer to the growth of the mystery cults in the pre-Christian era

>>2700116
Think Christianity with more fees and mysticism

>>2700116
They were mysterious.