The word agnostic is redundant.
The problem comes from the lack of definition of the word god.
Personally I am a strong atheist regarding the claims for the god of christianity. I am convinced beyond all reasonable doubt that Yahweh - the god and father of Jesus - does not exist. The same goes for Allah.
When people talk about the meaning of the term atheism they retreat into an impossibly vague notion of some undefined spirit. Nobody can give a sensible answer to such an ambiguous question so they take refuge in the agnostic word.
I think that is a mistake. Put the onus on the person asking the question to carefully explain the god they are taking about, then we can talk about it sensibly.