This afternoon, I had a brief discussion with the Rooster about non-belief-based involvement in religious ritual. The question he raised was whether an individual could eat Shabbat lunch every week and not be considered religious.
I don't know that eating lunch is a religious act. You can take place in a ritualistic custom that's based in religion without it being a religious custom. Is the ritual itself religious, simply because it originates in religion? Is it religious because you are engaging in it with people who endow it with religious significance? Why can't you take part in a ritual godlessly and it be secular? So much of what we do in everyday life has religiously ritualistic roots, down to our calender; just because something has religious importance to some people doesn't mean that engaging in it is a priori religious
In the interest of lengthening this post (because the burden's been unfairly on Annie for months now), I asked Balaam's Donkey, owner of two of the cutest dimples this side of the Great Divide, "If you do Shabbat lunch every Saturday, with the concomitant prayers, but without the belief in a deity or the religion, is that a religious act?"
His measured response: In that it is a practice with religious origins, but it is ostensibly social-cultural in its actual manifestation. See: Kaplan, Folkways; see Menachem Brinker (but that's a much larger conversation). It is a Jewish thing, but Judaism is not solely a religion today: making practices that are religious by design, not necessarily religious in practice, but essentially "Jewish things that Jews do." To what end? To paraphrase a professor of mine: "because we like it."
There you have it, folks, straight from the donkey's mouth.