How do you justify calling yourself a Church?
This was originally called a "church" because it amused me.
I continued that designation because it seems to work. It also permits our clergy to perform non-religious ceremonies, and within most US jurisdictions, to legally perform marriages for those who want the ceremony without the religion.
For more a more extensive discussion, please see one or more of the articles.
Feel free to contribute to the discussions through questions or an additional article or two.