Nietzsche wrote at length about the "death of god," which was his way of symbolizing the unseating of god from society's abstract throne, and the dangerous power vacuum that blood would be shed to re-fill. You can't walk three feet through the past couple centuries before finding some text discussing, cheering on or mourning the transition from a society where god is generally assumed to be behind things to one where he isn't.

If a similar phase change had occured 3000 years ago, I'm pretty sure it would have been well-documented. I have a hard time believing that this event is for the first time being seen clearly from a vantage point three thousand years distant!