From a discussion on Facebook that I will put my response here:
Gnosticism is a statement of special supernatural knowledge. If you are Gnostic you have special supernatural knowledge. If you are agnostic you don’t have special supernatural knowledge.
Theism is the belief in a deity or deities. If you are a Theist you believe in some form of deity. If you are aren’t a theist (or deist, or pantheist which are subsets of theist) then you are a not-theist, an atheist, one of the godless.
These two categories combine into four subsets:
The Gnostic Theist – I have special knowledge that god 100% exists.
The Agnostic Theist – I think that god exists, but I could be wrong.
The Agnostic Atheist – I’m not convinced that god exists, but I could be wrong (this is me btw)
The Gnostic Atheist – I have special knowledge that god does not exist, 100%.
I argue that the Gnostic Theist and the Gnostic Atheist do not exist, if some one had special knowledge over the debate, then the debate would be over. I think anyone that puts themselves into these categories doesn’t understand what special knowledge is
The use of the term Agnostic in the general population is due to the stigmatisation of the word Atheist. Atheists are said to be immoral, satan worshippers, blasphemers (okay that is true), and any number of other nasty things. Using the term Agnostic allows you to express disbelief in a socially acceptable way and a good number of “Agnostics” use it as a badge of “intellectual superiority” and hold themselves above both the theist and the atheist.
But also there is the problem of things being attached to atheism. All atheism is is a lack of belief in god(s). It doesn’t mean that you believe in science, evolution, and the big bang. You can be an atheist and believe in spirits and the supernatural, just not god(s).
If you really want to define what I am you should look into secular humanism as a philosophy. I just use atheist as a shorthand because secular humanism requires lots of explanation.