The ancient revolutions of the earth have brought forth its first Gods, new revolutions would produce new ones, if the old ones should chance to be forgotten.

Paul-Henri Thiry, Baron d’Holbach, The System of Nature, v.2, p. 120, 1770

Writing began some 5000 years ago; its invention was a revolutionary threshold which opened the door to collective learning, the recording of history and the sharing of ideas across geography, cultures and the ages.  Writing is an enduring legacy that outlasts cities, nations and empires; it often outlasts the ideas that inspired the words written.  Witness the Genesis tale of Noah, which was adapted from the Babylonian story of Utnapashtim, which itself was taken from the earlier Sumerian tale of King Ziasudra; this same story was simply re-purposed with different gods and different agendas for different audiences several times over two thousand years.  The oldest elements of the Hebrew Bible are thought to have been penned during the 10th Century BCE, about 3000 years ago.

But 3000 years ago–even 5000 years–is but a drop in the bucket of the history of our species.  Ninety-eight per cent of our history as a species is unrecorded.  This leaves some 200,000 years of Homo sapien religion/deities unaccounted for.  Who knows how many gods we’ve worshiped and forgotten in the tens of thousands of years before the written word?  To paraphrase cosmologist/astrophysicist Lawrence Krauss, we as a species have worshiped some 1000 gods in just the past five thousand years of documented global history.  Consider:  Of those 1000 above, to 999 of those gods we are all atheists today… 999 we no longer believe in; we freely admit we were wrong 999 times.  Okay, now think about this:  if you had a friend who was wrong 999 times in a row, really, how much stock would you put in him insisting he was right the 1000th?

 It is only be hearsay (by word of mouth passed down from generation to generation) that whole peoples adore the God of their fathers and of their priests:  authority, confidence, submission and custom with them take the place of conviction or of proofs:  they prostrate themselves and pray because their fathers taught them to prostrate themselves and pray, but why did their fathers fall on their knees?

— Percy Shelley, The Necessity of Atheism, 1811

 The pertinacity with which [a man] clings to blind opinions imbibed in his infancy, which interweave themselves with his existence, the consequent prejudice that warps his mind, that prevents its expansion, that renders him the slave of fiction, appears to doom him to continual error.

Paul-Henri Thiry, Baron d’Holbach, The System of Nature Preface, 1770