I tend to think that the meaning of "religion" tends to be: some think the biggest questions of life are so hard that we can't know for sure, others seem to take the attitude that if they're so big, then the answer to them would AFFECT HOW YOU LIVE YOUR LIFE, hence one can't be an agnostic (and here I'm talking of agnosticism not with respect to God but with respect to the kinds of metaphysical questions God would purport to be the answer to)....the latter seem to be the ones I'd call religious.
This is basically the difference between reasoning for purely theoretical reasons vs reasoning for practical reasons. I don't think in some ways that the compulsion to take sides on religion is that different from that in politics, which is also a far-from-detached, extremely opinionated space, where the compulsion to have a view is from a kind of practical reason: this affects us now.
In some ways, this is my biggest problem with all this. I'm viscerally against this idea, and I think it's almost without question unreasonable to suppose that, purely and completely on reasoning for knowing (not for acting) alone, there's a lot of difficulty in arriving at a definitive answer to the deepest metaphysical questions in life (the ones that sometimes are answered with appeal to God). In fact, not a small number of those who actively defend religious faiths using professional philosophy seem to hold a view like this: that at some level, reasoning alone can easily lead you in the agnostic direction.
Still, I think a lot of the thoughtful religious people don't have sympathy with this in the same way that a lot of politically active people don't have sympathy from people detached from politics.
They would view this attitude as an excuse to just go lead one's ordinary materialistic life without a spirituality.