They don't understand the difference between belief and faith. I believe many things, but have no faith in them. I will take contrary evidence into account.
I'm on mobile so won't type it super elaborately, but there is an interesting thing here about science education.
They don't really have the background to do elementary experiments to prove things, and many schools have under funded labs. Further many textbooks don't talk about the development of how we got to our current state; just how it works. More modern experiments require complex instruments; can't just borrow the large hadron collider for a weekend. As such we depend on papers published. I think that could give a similar vibe to Sunday School.
They got this part right though, since there's no way to prove the existence of A god (this is the agnosticism principle, others would accept the fact that no one can prove thebexitence as rpoof of its nonexistence), atheists must believe that that's the truth. Both theism and atheism are beliefs, and faith as I understand it in this context is a conviction based on belief, which again kind of applies.
Religion however is a faith system, the part where it's organised by people and has a structure around it, that's the part that atheism doesn't comply.
there's no wyantonrpove the existence of A god, atheists must believe that that's the truth.
What you're describing here is agnosticism, not atheism. Agnostics claim that the existence of God is either 1) not known, but certainly possible, or 2) unknowable to begin with.
Atheism, on the other hand,
is not an affirmative belief that there is no god nor does it answer any other question about what a person believes. It is simply a rejection of the assertion that there are gods. Atheism is too often defined incorrectly as a belief system. To be clear: Atheism is not a disbelief in gods or a denial of gods; it is a lack of belief in gods.
We are getting into semantics and philosophical concepts and I do mostly agree with you, but just to continue with the conversation:
Im looking at things in a very theoretical "not practical for the real world" kind of way here, because that's what all this discussion is about, conjecture and thought experiments. Although I agree that atheism is not a belief system, anything that we don't have certainty with we believe in, in fact anything we have certainty in and itself a belief on the amount of certainty we have. There's no absolute way of knowing anything with absolute certainty since in the real world there's been several times when our perception of reality has been broken and remodeled.
Going into a very very extreme, even if a water faucet worked as we expected 3 seconds ago we don't have absolute certainty that our water supply wasn't cut right now or any issue arised, so we decide as humans to believe in the certainty that our last observation in reality provided us.
Again, thought experiment, but atheism is kind of the same is a more obvious way, there's been no proof of godhoods both exitence and nonexistence in the history of humany, so any decision must be supported by the belief of it being certainty. Several people accept the fact that no proof of godhood has been provided as proof of the inverse (atheist gnostics) while some others don't think that's sufficient but also decide to believe in the nonexistence (agnostic atheists). In the same way, there's people that accept of the existence of a superior power while saying that there's no way of confirming it, which is why it's a matter of faith (agnostic theists); while other people decide that stuff said in some transcripts is proof for them to be certain about the fact and their faith is not directed into the existence of godhood itself, but to the character or dogma of it, or to the things they decided are the source of their certainty (gnostic theists).
BTW, the link you provided is from the American Atheists association, and as all abstract concepts they get developed and accepted with different interpretations, most equally valid.
Why did I spout all this thought gibberish? because this is how theologists think. If we want to discuss atheism with theists, this is how their brains will understand better the concepts of atheism, since that's how their brains think and accept belief and faith.
Between us atheists saying "I don't hold a belief let me alone" is enough, especially the "let me alone" part xD, but that's not going to shut up the pestering relatives, and I'll admit that it's fun to discuss of these concepts.
Yeah, I know that gnostic atheism is a theoretical position to hold, but I've never actually met an atheist that holds that view. The vast, vast majority of atheists ascribe to a scientific world view that is based around the concepts of evidence and burden or proof. As such, trying to argue belief in the non-existence of a non-existent being (i.e. "I firmly believe that God definitely doesn't exist") is not compatible with that logic, whereas "I don't believe in God, because there isn't enough evidence" is.
When it comes to explaining atheism to religious friends and family members, I've found the best approach to be this: Ask them if they believe in any other Gods except their own (Zeus, Ganesh, The Yellow Emperor, etc.) When they say no, you say "Ok, so my list of Gods I Don't Believe In is one longer than yours."
I'd say that, given what I explained, if your certainty based on the burden of proof, you are a gnostic by definition of the original word, gnosis (knowledge in Greek). You have a belief in the certainty of the proof, that if no knowledge exists of something, it doesn't exist (or is not relevant enough to discuss it).
In fact, most atheists I know of are gnostic too, in the literal sense of gnosticism not the heretical movement that appeared in the second century of the Christian church that I had no idea existed. Most agnostic people I know of don't subscribe to either atheism or theism, they just accept the uncertainty of the theos.
My relatives are way more annoying than that lol, getting into their theories and expanding on them usually hurts their brain and they leave me alone haha.
In any case, since this is mostly about the concepts of belief it will be hard to reach a consensus, so I'll leave at this. It was a pleasure discussing with you.