Check out agnostic history writer Tom Holland's Dominion, Christianity transformed ancient pagan society in many important ways. The West did not always have the moral values and theological assumptions it has today. To take one example, the poor were by and large ignored in Greco-Roman pagan antiquity. Charity was not common and "obvious" in the West prior to the arrival of Christianity.
Check out the book Inventing the Individual.
https://www.amazon.com/Inventing-Individual-Origins-Western-Liberalism/dp/0674417534
Reading it helped me realize just how infused secular western culture is with Christianity. Both western atheism and modern neo-pagan movements are infused with Christian values. It’s virtually inescapable. Something to think about