You’re confusing belief with knowledge.
If you don’t believe in a deity, guess what, you’re an atheist regardless of whether you know for sure a god doesn’t exist or not.
Most atheists are agnostic because it’s not on us to prove that a god doesn’t exist, no one should ever take the burden of proving a negative.
That’s not entirely true, most definitions of Agnosticism frame it as a different position from Atheism.
Plus, you don’t have to prove something to believe it, if you’re convinced that there is no god you can define yourself an Atheist, that’s it. Agnostics are just “on the fence” and have no horse in the race.
No.
If you’re not convinced a god exists you’re atheist, plain and simple.
Now, you can be a hard atheist where you know a god doesn’t exist, or a soft atheist where you don’t know.
Knowledge is a subset of belief. A belief when you have strong evidence is knowledge if you will. Like science.
Because one cannot choose a belief, you either are convinced or not, you can’t really be on the fence.
Wikipedia defines Agnosticism as:
the view or belief that the existence of God, of the divine or the supernatural is unknown or unknowable.
It is not related to actual knowledge. No matter the claims one can make, no one can be 100% sure whether a god exists or not. It’s called “faith” because people choose to believe despite the lack of irrefutable evidence.
Belief, on the other hand, is definitely a spectrum and you can be convinced or skeptical of affirmations from both sides. There’s also apatheists that simply don’t care whether it exists or not, or Ignostics that question the question itself. There’s plenty of people “on the fence”. The definition of Nontheism for example encompasses all those three, but not Atheism.
Agnostic Atheism is a position that’s very close to Atheism, but not all Agnostics are Agnostic Atheists.
