Bitcoin is as much a religion as money is a religion.

Its a social construct. If you want to call believing people born to the same parents as being more special requiring special obligations that other people wouldn't have, or adopted siblings, or step siblings (the concept of family which gets very messy when you look into it) a religion, you can go be weird by yourself.

However, economists do generally recognize the importance of "the faith of the currency". When your currency loses the "faith" of the people, you run into "sticky inflation". Look up the story of the Brazilian "real" to understand that.

But yes, you declare your belief in how the social construct is or ought to be by running your version of Bitcoin on your computer. When you network (both in the computer terminology and in the social worker "networking" terminology) you share in a monetary system called Bitcoin