Why Agnosticism?

[diffidus]

To not believe in God implies the belief that God does not exist.

Wrong, lacking a belief in god is not the same as claiming that there isn't one. I as an agnostic atheist am not claiming anything. No assertion made, I simply lack belief. It's not to difficult to understand.

Gnostic atheists are those who claim there is no god.
Agnostic atheists admit to not knowing whether there is a god or not but ultimately reject the idea.

If what you are saying is true, then we all here poses a belief (assertion according to you) that Santa does not exist.
Atheism is not a religion, it isn't faith-based. Atheism in it's most basic sense is the lack of belief in the existence of god. Nothing more, nothing less.

I do not believe in god, it doesn't get much simpler than that.

Diffidus

That's not quite what I said. Claiming that God does not exist is not the same as believing that God does not exist.
Imagine saying to a crowd of people, ' I believe that cars do not exist.' Do you think it would mean anything different to the crowd if you stated, 'I do not believe cars exist.'??

Both sentences have an oject which is a car. The car is a conceptual idea that we are holding in our mind and the predicate, namely, that cars don't exist, is a view that states a belief about the car i.e. that in the real world it does not exist. Unless this can be shown to be a fact, such as, the internal angles of a triangle in Euclidean geometry add up to 180 degrees, then it must taken as a belief.

Thank you for your definition of agnostic atheist, I had not seen this before. However, even on this definition, if you do not know whether God exists or not then there is no firm basis for rejecting the idea and, therefore, the act of rejecting must be based upon an act of faith.