False perceptions about Atheism and Agnosticism

[smax]

Theism is "I believe in a god" yeah?

The prefix 'a' means 'not' or 'without'

Thus, semantically speaking, atheism means "I don't believe in a god" but the semantics behind it are irrelevant since it still carries the same meaning today.

Wait...

Nope, the “a” does not modify “ism” as you seem to have asserted, it modifies “the”, so the word literally means a belief in no God. That’s still a belief, not a lack of belief.

Can you show this to be true?

Wait again, still doesn't matter. Pulled up the origin of the word and the meanings it carried, originally:
1. without gods
2. denying or disdaining the gods (especially officially sanctioned gods)
3. generally: godless, secular
4. abandoned by the gods

So it can mean any of those 4. Is it fair to say that the people who define themselves as atheists today should choose the definition? If not; meh. I'll just call myself the 'godless type' of atheist if the definition is ever brought into question.

The greeks used this word to describe a people they knew believed in a deity, just not their deities (plural).

This fact alone proves that the word was not intended to describe people who deny the existence of god in any general sense. The word was intended to describe people who do not accept a particular god (or gods).

Early Christians did not accept the gods of the state.

Atheists simply accept no gods because the evidence hasn't compelled them to.