He begins with a chapter called ‘The Great Rebellion’, in which he describes the sheer outrageousness of Christianity in the world of late antiquity. At the risk of vast generalisation, Indo-European paganism – the type which characterised the entire known world, from Scotland to Persia and beyond – held that the world consisted of a vast cosmic hierarchy, with the highest god at the top, and beneath it a descending order of lesser gods, demons, spirits, thrones, dominions, kings, princes, priests, prophets, merchants, artisans, peasants and slaves. In this sense, and in this sense only, was the ancient world in any way ‘pluralistic’ or ‘tolerant’: it was tolerant of new gods, but only insofar as they fitted into the existing structure without attempting to overturn it (which is why almost all new religions were tolerated, even welcomed, yet at the same time monotheism was a big problem, and Plato’s Laws explained that atheism was a matter for imprisonment, or even death). In this context, the gospel was appalling, Christians were seditious, and

… it was no more than civic prudence to detest them for refusing to honour the gods of their ancestors, for scorning the common good, and for advancing the grotesque and shameful claim that all gods and spirits had been made subject to a crucified criminal from Galilee – one who during his life had consorted with peasants and harlots, lepers and lunatics. This was far worse than mere irreverence; it was pure and misanthropic perversity; it was anarchy.

 
For Celsus, one of Christianity’s earliest critics, a huge problem with this cosmic sedition was its multiracial dimension: pagan gods served to unite the worshipper with his nation, and would certainly not be caught saying anything so absurd as ‘there is neither Jew nor Gentile, slave nor free’. Paganism could tolerate many things – poverty, bloodthirsty games, the exposure of infants, crucifixion – but it could not abide the overthrow of the cosmic order by a multiracial bunch of oddballs who denied the pantheon, worshipped no images and offered no sacrifices. Christianity may have been exclusive in a doctrinal and ecclesiological sense, but when considered socially, racially and nationally, it was the most radically inclusive idea that anybody had ever come across.
 
Hart’s next article, ‘A Glorious Sadness’, explores the difference between the melancholy of the ancient world, as it appears in the world-denying philosophies of Gnosticism and Platonism and the grim acceptance of reality found in Stoicism, and the profoundly creation-affirming Christian message of redemption, resurrection, glorification, and ‘good news of great joy for all the peoples’. The subsequent chapter, ‘A Liberating Message’, discusses the impact of the gospel upon foreigners, the weak, the poor, and women, and shows emphatically how generous, radical and sacrificial the early church’s attitude to the downtrodden was. Next, ‘The Face of the Faceless’ begins with the story of Peter’s denial, and points out that, for all that we read it as a story full of tragedy and emotion, literate ancients would have disregarded Peter as unworthy of sympathy or even interest, simply because a man of his class would not have possessed the dignity necessary to summon a sense of pathos from the well-bred reader. The reason for that, Hart argues, is that in the early Christian writings,

… we see something beginning to emerge from darkness into full visibility, arguably for the first time in our history: the human person as such, invested with an intrinsic and inviolable dignity, and possessed of an infinite value.

 
In the gospels, and other documents from the early church, we find an interest in human beings as persons, with no account taken of their social standing or fitness to interact with others – and we also find numerous instructions to Christians to disregard the social rules of hierarchy and class, and privilege nobody over anybody else. Contemporary Britain may take that for granted, of course, but (a) the ancient world most definitely did not, and in fact found it either nauseating or scandalous, and (b) the only reason we do take it for granted is that we are a society that, for better or for worse, is functionally post-Christian, and has had its values shaped for centuries by the worship of the God-man who humbled himself to become a slave. Commenting on a sermon by Gregory of Nyssa, Hart argues:

Modern persons of a secularist bent, who believe that the roots of their solicitude for human equality reach down no deeper in the soil of history than the so-called Age of Enlightenment, often tend to imagine that their values are nothing more than the rational impulses of any sane conscience unencumbered by prejudice. But this is nonsense. There is no such thing as ‘enlightened’ morality, if by that one means an ethics written on the fabric of our nature, which anyone can discover simply by the light of disinterested reason … Whatever it is we think we mean by human ‘equality’, we are able to presume the moral weight of such a notion only because far deeper down in the historical strata of our shared Western consciousness we retain the memory of an unanticipated moment of spiritual awakening, a delighted and astonished intellectual response to a single historical event: the proclamation of Easter.

 
Hart then describes the way in which the Roman Empire became officially tolerant of Christianity, and then officially Christian, in ‘The Death and Rebirth of Worlds’, before concluding this gripping section with a chapter on ‘Divine Humanity’, in which the shocking implications of the incarnation for our anthropology, historiography and morality are articulated:

In short, the rise of Christianity produced consequences so immense that it can almost be said to have begun the world anew: to have ‘invented’ the human, to have bequeathed us our most basic concept of nature, to have determined our vision of the cosmos and our place in it, and to have shaped all of us (to one degree or another) in the deepest reaches of consciousness … ‘Christendom’ was only the outward, sometimes majestic, but always defective form of the interaction between the gospel and the intractable stuff of human habit. The more vital and essential victory of Christianity lay in the strange, impractical, altogether unworldly tenderness of the moral intuitions it succeeded in sowing in human consciences … To look on the child whom our ancient ancestors would have seen as somehow unwholesome or as a worthless burden, and would have abandoned to fate, and to see in him or her instead a person worthy of all affection – resplendent with divine glory, ominous with an absolute demand upon our consciences, evoking our love and our reverence – is to be set free from mere elemental existence, and from those natural limitations that pre-Christian persons took to be the very definition of reality.

 
It is common, almost fashionable, to decry the early centuries of the Catholic church as an era marked by mistakes – cessationism, paedobaptism, Constantinianism, episcopalianism, sacramentalism – and I have allowed myself to speak of it that way as well. So it’s refreshing to read an Orthodox writer as he describes the transformation the gospel brought to Europe, and to reflect happily on the power of God, in Christ Jesus, by the Spirit, through the church, to overthrow kingdoms, renew minds and transform cultures. Or, with an impish sideways glance to James Davison Hunter, to remember the time when Christianity changed the world.