If you don't hold a belief in a God(s) You are an atheist. If you do hold belief in a God(s) you're a theist.
As an example, a Buddhist could be an atheist since the following of Buddhism does not entail belief in a God(s) I found this from Buddhanet.net
A lot of people take atheism to mean you're the guy that rejects everyone's beleifs. An atheist can be just as spiritual as any theist.
As an example, a Buddhist could be an atheist since the following of Buddhism does not entail belief in a God(s) I found this from Buddhanet.net
1. There is no almighty God in Buddhism. There is no one to hand out rewards or punishments on a supposedly Judgement Day.
2. Buddhism is strictly not a religion in the context of being a faith and worship owing allegiance to a supernatural being.
3. No saviour concept in Buddhism. A Buddha is not a saviour who saves others by his personal salvation. Although a Buddhist seeks refuge in the Buddha as his incomparable guide who indicates the path of purity, he makes no servile surrender. A Buddhist does not think that he can gain purity merely by seeking refuge in the Buddha or by mere faith in Him. It is not within the power of a Buddha to wash away the impurities of others
4. A Buddha is not an incarnation of a god/God (as claimed by some Hindu followers). The relationship between a Buddha and his disciples and followers is that of a teacher and student.
A lot of people take atheism to mean you're the guy that rejects everyone's beleifs. An atheist can be just as spiritual as any theist.