@Elmud,
The Bible is more history than anything else. There is mysticism, and story-telling : rationalisation thrown in; yes, but all of this tries to explain why certain societies crashed and burned, and why other's survived.
Some may dispute just how accurate that history is, fair enough, but no better record exists. And, even the ancient Greek religions, myth if you will, are still based somewhat on real experiences.
A world without religion is a world without story-telling, the basis of history. Its a world without memory. Religion is the origin of language. First the stories are passed down verbally, then recorded in stone, then paper. Our first books were religious. Our earliest manuscripts are religious. Earliest courts were religious. Earliest laws. Earliest economic policies. Capitalism and communism are both ideals that were born from Bible stories. (Do not steal, give alms to the poor)
Without religion there would be no ethics, no language, no math, no science, no philosophy, no education, no law, no structure. We would be little more than cave-men. Our population would grow to the point of outstripping its ability to survive in its environment - extreme hunger would follow - then hunger-madness - then war.
The survivors would try and mime the events which led to the destruction of the previous 'society'. As the mime became better performed, language would evolve, story-telling, then those who remembered how the destruction started with theft, over-population through uncontrolled breeding and other such 'immoral' behaviour would create rituals to remember it all by : Religion.
Eventually society would be more stable - except that it would always be bumping itself against the environment. As the society became massive, its single biggest threat would be its tendency to cause extreme amounts of heat-energy. The ice-caps would melt, and the survivors would tell the story of a great flood.
Every 50 000 years, the ice caps melt.
About the same amount of time it takes for the human population to reach an exponentially increasing population boom.
Do the math.