Resolved, that the members of ‘the church’ are those people — reasserter, reappraiser, Jew, Hindu, Muslim, Buddhist, etc. — who are willing:
1) to pray ‘next to’ one another, even if the prayer of the person next to you is no more than a grudging acknowledgement that maybe a Creator of some sort might indeed exist;
2) to treat each other's prayers with equal dignity, even when there’s grave disagreement over underlying suppositions; and
3) to collaborate in seeking the best for others as for themselves, even if for no other reason than that this seems to give a species a survival advantage over the long term.
Under this definition of ‘church,’ a given individual’s theological beliefs would be of no particular relevance, except of course to the extent those beliefs influenced the individual’s actions.
I know some would object to such a definition of ‘church’; I’m curious how you’d articulate that objection.