Sincerely, All agnostics
Well, to be technical…
Agnosticism is the stance that ultimately the existence of a god or gods is unknowable.
Atheism is the lack of belief in a god.
So it is possible to be an agnostic atheist, as I am and as are most atheists. I acknowledge that ultimately it is impossible to prove or disprove a god’s existence, but I personally see no reason to believe in one.
Likewise, it is possible to be an agnostic theist, which is belief in a god but acknowledging that ultimately your god’s existence can’t be proved.
Many people think that an atheist is someone who is certain that a god does not exist. This would be a gnostic atheist, and in my experience people with this viewpoint are in the minority.
On the other hand, gnostic theists, that is, people who are certain that a god exists, are very common.
Here’s a handy-dandy chart with circles and stuff.