//But are they as lacking of proof as the believers ?//
Not really. Believers present their holy books as evidence of a supernatural, omnipotent, omniscient, omnipresent creator god who goes by various names, most commonly Yahweh, Elohim, Jehovah, and Allah. Whilst atheists can no more disprove the existence of a creator god than believers can prove it, atheists who know the holy books well are quite capable of rationally, and unarguably, negating the evidence presented that this particular god is what he is claimed to be. Quite simply, if such a god does exist, logically, it can’t be him.