Atheism worships a dead god.

[TheDarkestOfAngels]

The idea that 'You can't prove a negative' is a common misconception and a fallacy... and one that we atheists are guilty of more than probably anyone. Simply apply the idea to things other than the existence of god(s) and it quickly becomes clear that you can, indeed, prove a negative assertion to be true. When it comes to the existence of god(s), however, the claim of existence cannot be proven nor disproved. This is due to the lack of a single and coherent definition of what a 'god' is. In spite of this, when one looks at the question with intellectual honesty, it can be said that there is a preponderance of evidence to suggest that the existence of god(s) is astronomically unlikely and completely unnecessary.

It's not just that. It's also that we're constantly being asked to prove that the existance of god is unproven when we say that god doesn't exist precisely because there is no evidence for it.
The fact that no one can seemingly agree on who or what god is is another factor in this mess.
Some people seem to like to give god attirbutes that specifically defy abilities to measure his existence scientifically while others will flatly state that science is wrong when it claims something that goes against their beliefs (such as evolution vs. creationism.)

This is basically why proving a negative is a fallacy - particularly since atheists by definition are people who do not buy into certain religious beliefs.

Your talk of 'no proof of existence or lack of existence' as proof of nothing only goes to the point that I, for example, cannot prove that god or godlike beings are impossible. Certainly a civilization advanced enough will appear godlike to us, much as we would to primative humans who have been isolated from the rest of the world.
For example, our medical ability allows us to legally kill a person in order to cure them of certain ailments - such as many intensive heart surgeries that literally require the heart to be stopped during certain procedures. We can reattach severed limbs, create prosthetic limbs that are becoming increasingly more like the ones we lost, and we're now getting closer and closer to being able to regrow lost body parts.
There may even be beings that defy what we understand to be conventional physics (any sufficiently advanced technology is indistinguishable from magic) and knowledge. However, the ideas of god and gods that have been passed down from the primative men (and women, if they were allowed to read and write during that age) who concieved of them can be easily disproven by their lack of proof.
However, religion has given us specific actions and parameters of what these divine beings can do and what they have done. When asked to prove that these beings do not exist, it becomes as easy as simply proving that there is no real evidence that they have had any influence on anything we know of and they have had no real interaction with any human being on the planet and that certain events either never happened or they happened in a manner not requiring the intervention of a "supernatural" being.
As such, their arguements become invalid by definition - they need to prove their religion is true by providing evidence that it happened to counter the evidence that they didn't.
Evolution vs. creationism is a fantasic example of this.