But the only thing necessary to be an actual bona fide atheist is to not hold the belief that God (or gods) exist (or for Jan's benefit, Is).
If one wishes to refer to a certain subset that is absolutely fine, but one should surely not generalise to the whole in doing so?
An atheist is a person who does not believe in God, and a theist is a person who believes in God.
To ''not hold the belief that God does not exist' (whatever that means), is but a reason one does not believe in God.
jan.