Monotheists all believe in one god and disavow the rest. If mankind believes in 3000 gods, then all monotheists don't believe in 2999 of them. Atheists are more consistent and don't believe in all 3000.

Although, entirely by accident, the discovery of evolution DOES disprove the Christian god. By proving that Adam and Eve were mythical figures, and that The Fall never happened, the whole basis for the crucifixion disappears, as does the purported need for redemption. It's all bullshit. Christianity is proven to be bullshit because it based itself on myths the authors never expected to be invalidated. That invalidation comes purely as corollary; evolution has nothing to say about Christianity. Archeology also disproves the Exodus. Western religion has far more flaws than wisdom. Many of those flaws being exposed by the social improvements of moral awareness.