Centurion's Daughter marks the very beginnings of western Christendom, a civilisation that would reach fruition in the Middle Ages before changing into modern European culture that eventually became the world culture.
But what exactly is meant by 'Christendom'? It's a question worth answering since our conception of Christendom and Mediaeval civilisation is almost inevitably a caricature. The world we live in now is so fundamentally different from the world as it was then that it is very, very difficult to grasp the thinking of people of that time. One automatically conjures up a picture of religious intolerance, bigoted narrow-mindedness and backwardness, all mixed with a propensity for violence and a low respect for life. It's the backdrop of nearly all the big Mediaeval movies (oh, yes, and they hadn't discovered soap either).
The truth is different. I can pick out a few things from the society of Christendom that set it apart from the world we live in now, but which do not add up to a straw man.
1. Social institutions respected and actively upheld the people's deepest convictions.
The secular state did not exist. It was inconceivable that the government and legal system should not support the beliefs and moral values of the majority of the population. This applied everywhere, not just in Christian Europe. Contrary to popular conception, religious minorities were rarely persecuted for their religion. They were left with their own beliefs provided they did nothing to disturb the social order built on the religion of the majority. That included proselytising, which inevitably led to religious civil war. The Inquisition was actually set up not to torture Protestants or Jews, but to prevent the social fabric from being ripped apart, something which happened when a heterodox movement took root in a region. Once it had gained converts it inevitably raised an army. The idea of accepting a government that did not actively endorse the beliefs and moral values of its citizens was simply unthinkable. That came later.
2. There was no such thing as social climbing.
One of the lynchpins of modern society is the belief in material success. The idea that with hard work, positive thinking and the right skills one can rise up the ladder of a society in which social prestige is built exclusively on wealth. That didn't exist then. True, social prestige did to a large extent depend on wealth, but wealth could only be born into; it could not be made by fair means or foul. Which meant that the acquisition of money was not a primary objective of life. Other things had more importance. Looking after one's family or fulfilling ordinary obligations were honourable in themselves. For the wealthy class the notion of chivalry took hold, using one's wealth and power to protect the less fortunate, not prey on them. In a word, there was a sense of place, staying where one belonged and doing one's job in one's slot in the world. Sure, there was always room for greed and ambition since mediaeval society, like modern society, was composed of humans, but the fundamental outlook was different.
3. Material improvement was not a priority
Christendom was a highly conservative society, which meant that technologically very little changed for centuries after the fall of Rome. The Mediaevals did things the way their fathers had done them and did not try to find ingenious ways of doing them better. I put it down largely to something which the Mediaevals understood and we have somehow forgotten - the fact that there is no cure for death. We live, if we are lucky, seventy or eighty years, then we die. Everything we have built up in this life we will lose at death. We will be torn away from our possessions, occupations, social prestige, projects, friends, family, everything. All these things in themselves do not matter. They only matter inasmuch as they have a bearing on a future existence that will not end. It is only when the idea arose that this life is all we have and we must make the best of it, that the impetus was given to material improvement. Today the drive for material improvement is all-encompassing and it is killing us. The Mediaevals had no notion of it.
Was Christendom a better system than the one we have now? One thing it did do at least was to prevent the nightmarish excesses of a secular system in which power is ultimately under no moral constraint. The Holocaust, the Gulag, the Cultural Revolution, the World War are children of the secular world, not of the Mediaeval. Compare about 4,000 executions by the Spanish Inquisition in its 350 years existence with 6,000,000 Jews over four years and 10,000,000 Kulaks over two. These horrors could not have arisen in the Middle Ages.
The question ultimately is a moot one. The ideas of religion as having a public as well as a private aspect, life as a sense of place, and contentment with a modest material lifestyle, are long gone. We are seculars to a greater or lesser degree and have no choice but to make the best we can of a secular world.