What is the purpose of the church?

Reposting this question I asked on r/Episcopalian because I'd like to get the perspective of both global Anglicans and of ACNA folks.

I have my own opinion on this, of course. But I'm just curious what types of views there are on what exactly the church's primary purpose(s) is/are. Specifically, what makes the Christian church distinct from other nonprofit institutions (secular or non-Christian religious) and what makes Anglicanism distinct from other churches?

To be clear, I'm not looking for the catechetical answer, nor the academic perspective. The core of the question I'm asking, put another way, is: Why should someone be Christian, why should someone join a church, and why should someone specifically be Anglican (in the case of ACNA, why not be Episcopal, and for Episcopalians why not ACNA)?