Maybe you ought to rethink this line of attack.
Ehhh... no. I don't particularly feel like discussing whether or not god exists right now, but I do feel the need to stick up for the scientific method.
Affirmative assertions require evidence. You do not need to prove that something doesn't exist. You do need to prove that it does. I could assert that you are actually made of pudding. But there would be no reason to give credence to that assertion without evidence. I can't prove that the Flying Spaghetti Monster doesn't exist, but there's no evidence that it does, so I can safely make decisions while relying on the idea that doesn't. Also, absence of evidence really is evidence of absence. There are no dodos around anymore. We know this not because there was a general memo from the Earth that dodos were now gone, but because there were dodos and now no longer are. There is no evidence that dodos are gone, but no evidence that they are still here. We conclude that dodos are extinct. We concluded the same about coelacanths, too, until evidence disproved that conclusion.
We conclude that Zeus and Ares don't exist because we climbed Mt. Olympus and no one was there. There is no physical evidence that leads to the conclusion "because this exists, Ares cannot", but a lack of evidence for Ares leads us to conclude that he doesn't exist.
So, no. There is nothing fallacious about the conclusion that god doesn't exist in the absence of evidence to support his existence. And the statement "god exists" does not require the same proof as "god doesn't exist." The former requires that evidence be discovered that can only be there due to the existence of god, whereas the latter merely requires showing that the evidence for the former is not genuine.
Let's take the Shroud of Turin as an example. It was put forth as evidence for the crucifixion of Jesus. Does this prove anything, though? It is merely a shroud that looks to be imprinted with the outline of a crucified man. Does it really demonstrate which man? Was it discovered in a tomb marked "Jesus of Nazareth"? No. All it really shows is that men were crucified, which we all already know. That the shroud was later tested and shown to only be about 700 or 800 years old further disqualifies it as evidence for any spiritual claims.
Your original post about god was actually a nonsequitor. This thread is asking about what in the human psyche would cause us to imagine gods. Its premise requires that god not exist. Unless you have evidence of a natural god radar in the human mind, the existence of god has no bearing on why humans would invent one. We are banned from asserting the nonexistence of god in religious forum threads. How about you show us the same respect and not derail this one any more than you have?