Beware of identifying in general. "We" are all quite different. Few if any of "us" can be considered reasonably rational by the standards of this site.

That's a good point, which I'll watch out for in the future.

With a sizable minority of theists here, why is this even an issue, except maybe for some heavily religious newcomers?

One thing I didn't specify is that this applies to discussions with non-LessWrongers about religion (or about LessWrong). On the site, there's no point in bothering with this identification process, because we're more likely to notice that we're generalizing and ask for an elaboration.