One of the common arguments leveled against Christianity is that it is an intolerant system used to subject people to a false being and dictatorial being.
I will take the position that:
Christianity took root in Europe where vanquishing one’s foes in bloody conquest was the surest method for acquiring immortality.
So in the notion of a savior, a single human sacrifice to end all other human sacrifices, was borne the idea that one could live eternally without spilling the blood of one’s enemies, that self-sacrifice was the key to immortality, and not the sacrifice of others.
This was a superior method to Roman, ‘Glory’, that Christian, ‘Grace’, was a preferrable condition.
People point to the diminishment of arts and sciences in the ‘Dark Ages’, though recent research suggests that this belief is more hype than actuality. However, regardless of it’s specific veracity, the heights of Graeco-Roman accomplishment were limited mainly to the Patrician class with a small nod to the power of the Plebes as represented by the ‘Mob’ of Rome.
Christianity was universal in that it allowed for an adherence to a social order that went beyond the affiliation with a particular tribe and welcomed members from any and all tribes. Roman multiculturalism suited this well, and it took root first within the slave class in Roman society and grew into the class of freemen Plebeians until it became an integral part of the social order and was ultimately adopted, providing for a commonality of the ‘in-group’ that went beyond the boundaries of class, language and lineage.
That regardless of the veracity of the core beliefs, this was a social good, as it ultimately led to the greater acceptance of multiple cultures in the modern world, and has resulted in a net reduction of conquest, even if it did nothing to eliminate the savage brutality inherent in the human condition. While much violence was carried out in the name of the religion, the greater and more vicious violence throughout history has been carried out by the competing tribal nationalisms that existed within Christendom.
So from a sociological point of view, the notion that self-sacrifice is the key to immortality rather than glory on the battlefield, led to a more compassionate society.