We know that the Passions are a religion or a set of superstitions from Thaylenah. But what are the "Passions" exactly? Are they a group of Gods who represent various kinds of "Passion" worshipped by the Thaylen people? If not, are those "Passions" simply a set of ideals believed by the Thaylen people? Are there any connections between Thaylen Passions and Alethi Thrill?
The Passions could be called a religion, but there are those among the Thaylens (and to a lesser extent, other peoples) who would argue that it's more a philosophy. Or a companion religion. Much like Shinto and/or Confucianism co-exist in some places with Buddhism.
However, there is not formalized theology, despite various thinkers and gurus expressing their thoughts on the matter. The central idea is that Passion equates to Action, and the cosmic belief that wanting something draws it to you. This idea is reinforced by the spren, obviously.
Ah, so basically some people treat it as a fundamental way of life, and some people just treat it as The Secret?
Yes, you can see it as a Rosharan version of the Law of Attraction, though some people have taken it further into a more religious fundamental.