Just finished dominion by Tom Holland And here are some thoughts.
Western culture including secularism and humanism have inherently Christian values that drive them.
The cross is significant
The cross, and the symbolism of the Crucified God, the powerful humbling themselves for the powerless, is the key aspect of Christianity.
Christian civil wars
There is an ongoing tension between the letter and spirit of the laws.
The abolition of slavery seems like the most unexpected event. It almost feels as though it was purely the work Benjamin lay. Certainly most cultures didn’t see it as an issue but only appealing to Christian ideas of a common ancestory and the equality of all (no male/female, Jew/Greek) saw it as wrong.