"...attending a secular church is being religious. You may have no deity involved, but you are going through the motions of a religion."

You're making a claim, here, that there is a fixed definition of religion, and that it doesn't necessarily involve a deity. In fact, defining "religion" is very dfficult, but most definition do involve a deity (or, at the least a transcendent being, thing or principle). There is no firm definition in US law: https://digitalcommons.law.yale.edu/cgi/viewcontent.cgi?article=7793&context=ylj

(link goes to a 32-page PDF)

...or UK law:

https://www.cambridge.org/core/journals/ecclesiastical-law-journal/article/clarifying-the-definition-of-religion-under-english-law-the-need-for-a-universal-definition/BCD3B0A35753EACC5DCFFF7E6AAE8F90

If you believe that a set of behaviours ("going through the motions") is what defines religion, I would ask you what, then, defines superstition?