If “religion” is essentially institutional, then believing and confessing “Mohammed is a true prophet” or “Jesus is Lord” isn’t necessarily religious. Which is absurd.
But if “religion” broadly encompasses “any set of values, beliefs, and practices”, then almost everything we do, including almost everything the government does, is religious.
That “Congress shall make no law respecting an establishment of religion” is either a narrow or broad restriction, depending on the definition of “religion.”
This reminds me of “philosophy”, which is at minimum just “a way of thinking.” Everyone thinks. Some people are just more thoughtful about their thinking than others. So, your philosophy might not be that philosophical, but it’s still a philosophy. Or something like that.
It is for these reasons that I do not like the terms “religion” and “philosophy”, or “religious” and “philosophical”. People are in denial about just how broad and thorough and pervasive their own philosophy and religion are. Using terms like “religion” and “philosophy” feed our comfortable delusions of compartmentalization. They give us a false sense of security in the supposed sacred vs. secular divide.
We are living, walking, talking, working, breathing centers of beliefs, practices, thoughts, values, and feelings.