Indeed, and that makes discussion of it impossible. Hence why I find it silly to follow that standard.
There’s no way to talk about Christianity when:
Some believe in God
Some don’t believe in God
Some believe God is actually the devil
Some believe Jesus was God
Some believe Jesus was just a man
Some believe Jesus was the false prophet and it was John the Baptist who was the true prophet
Some believe there’s a Hell
Some don’t believe there’s a Hell
Some believe there’s Heaven
Some don’t believe there’s Heaven
Some believe that we have a soul
Some don’t believe that we have a soul
Technically, between all the variants of Christianity, there’s zero theological overlap. So for all practical conversations on Christianity, if you want to be inclusive and understanding of everyone, there’s exactly zilch you can talk about. The term “Christianity” means nothing and just plain off can’t even be used.
If there was no commonly accepted, majority that a reasonable person would assume upon hearing the word, “Christianity”, then I’d go along with laborious definition crafting. But that’s not the way it is. Most people are aware of the protestant/catholic split in terms of there being a Pope or no-Pope. But otherwise I wouldn’t expect your average person to know whether his own church believes in or doesn’t believe in angels, and I wouldn’t except him to know what various policies are on the afterlife, or any other sort of theological talking points. All he will know is whether something is or isn’t commonly related to Christianity, even if he himself doesn’t believe in it.
If I talk about Christianity and Hell, there’s no reasonable-minded native English speaker who’s going to be perplexed that the one could possibly be attached to the other. Just watching Tom & Jerry as a kid, you’d see angels and devils on everyone’s shoulders telling them to be good or bad. It’s unavoidable to have Hell associated with Christianity, even if you don’t personally subscribe to that belief.
Conversation is based on basic assumptions. There’s no ability to discuss any concrete topic unless we make assumptions that we share a common set of abstract knowledge.
NASA is “An American group that makes and flies spacecraft.” I can reasonably assume that that will be understood by anyone without having to lay it out ahead of time. I wouldn’t expect them to know that NASA is also the world center for tracking climate data, or any other such fiddly stuff.
But now, if someone complains to me because I’m assuming that NASA makes spacecraft–when really they just outsource it to other businesses–then I’d really rather just say that person is nitpicking for no other sake than the sheer glory of being able to nitpick.
Another person could get up and say, “NASA doesn’t build spacecraft, they just take money and burn it up as they litter astronaut bodies over American soil!”
Yet another person could say, “I work for NASA, and in my view, all NASA is is a bureaucracy that can’t find it’s own hand to wipe with!”
They might disagree with the basic, assumed knowledge of who NASA is, but they’re just being assholes to pretend like they don’t know what that assumed knowledge is. I realize that nitpicking is the favorite hobby of most of the SDMB, but there is a point at which you’re not actually nitpicking. All you’re really doing is trying to bully people into your own minority political belief and/or derailing the main topic in favor of meaningless minutiae.