That might be putting it a bit strongly. "western civilization" derives from ancient greek society, which wasn't christian, but contained many concepts that are considered foundational to our society (such as democracy).
Few books have ever had such penetration of a culture. The Koran, the Analects, the Pali Canon are perhaps the only meaningful comparisons.
Before that familiarity came from weekly readings at Mass, which is why I talked about partial familiarity for the thousand years prior.
I'm an atheist, but there's a difference between dismissing the book's contents and dismissing the impact and influence of the book's contents.
http://www.thebricktestament.com/
https://www.amazon.com/Book-Genesis-Illustrated-R-Crumb/dp/0...
And there are also people who e.g. carefully count the details, so that we don't have to:
https://dwindlinginunbelief.blogspot.com/2006/08/who-has-kil...
But of course always check the references. Use the work of textual critics to establish what is in which version of the original text, and compare.