Atheist or Agnostic?

[FatAndFaithless]

You could just call them nonbelievers.

From the way I have heard both atheists and agnostics talk, an atheist tends to claim that there is no God or gods while an agnostic is open to the possibility but does not have enough evidence either way to make a choice.

Both atheists and agnostics can either be spiritual or non-spiritual.

Some atheists will make that claim, but that's not what the definition of 'atheism' is. Hell, most atheists I hang around (myself included) would never make the claim 'God does not exist', because it's a positive claim that requires evidence.