I agree that political speech is typically sophistical. But building a state on the absolutes of a countercultural vision like Jesus's is absurd. The kind of sophistry needed to paper over those self-contradictions is no ordinary politicking.

Christendom was a long detour from ancient Greco-Roman paganism to modernity. The adjustments needed to extend classical pride in manliness to humanistic pride in personhood would have been relatively slight: simply follow the proto-scientific, naturalistic mindset and study more of human nature to discover the similarities between slaves and freemen, women and men, and so on. If Rome hadn't adopted Christianity, we could have had the Scientific Revolution before 1,000 CE.

Paul Johnson talks about the “total society” of the medieval Church, in “A History of Christianity”:

“In Milan, Augustine had seen the Church, through the person of a shrewd and magisterial prelate, helping to run an empire. His creative mind leapt ahead to draw conclusions and outline possibilities. In Milan the Church was already behaving like an international organization; it would soon be universal. It was already coextensive with the empire; it would ultimately be coextensive with humanity, and thus impervious to political change and the vicissitudes of fortune. This was God’s plan…

“But the idea of a total Christian society necessarily included the idea of a compulsory society. People could not choose to belong or not to belong. That included the Donatists. Augustine did not shrink from the logic of his position.”

And later, about the “total society” from 1054-1500:

“One of the great tragedies of human history—and the central tragedy of Christianity—is the break-up of the harmonious world-order which had evolved, in the Dark Ages, on a Christian basis. Men had agreed, or at least had appeared to agree, on an all-enveloping theory of society which not only aligned virtue with law and practice, but allotted to everyone in it precise, Christian-oriented tasks. There need be no arguments or divisions because everyone endorsed the principles on which the system was run. They had to. Membership of the society, and acceptance of its rules, was ensured by baptism, which was compulsory and irrevocable. The unbaptized, that is the Jews, were not members of the society at all; their lives were spared but otherwise they had no rights. Those who, in effect, renounced their baptism by infidelity or heresy, were killed. For the remainder, there was total agreement and total commitment. The points on which men argued were slender, compared to the huge areas of complete acquiescence which embraced almost every aspect of their lives.”