Originally published at the Huffington Post.

Throngs of people gathered last week in Sorrento’s Piazza Tasso for what might be called a faith-based fireworks display. Hundreds of rockets and roman candles were shot from the roof of the sanctuary of the Chiesa del Carmine, a church that dates back to the middle of the third century CE. Tourists broke into applause at the illuminated sky, but most probably had no idea what was behind the celebration — a knowledge gap hinting at a spiritual deficit that defines the modern age.

Sorrento locals were celebrating the feast of Santa Carmine, an event repeated all over Italy, in which Catholic saints are regularly honored with special masses amid festive parties, flea markets, and fireworks. I’ve been traveling to Italy nearly every year for a decade, and I often find myself caught up in one of these celebrations.

The feasts honoring the saints are intended as reminders: a prod to reflect on the lives of exemplary Christians and their contribution to the church and the wider society. But let’s be realistic: do most people see any connection between historic Christianity and the world around them? What stands out instead is a collective amnesia about the spiritual foundations of modern life.

Take just one example: the commitment of liberal democracies to care for “the least of these” among us.

I was reminded of this during a recent trip to Ventotene, a beautiful little island in the Tyrrhenian Sea, off the coast of Naples. The island was the birthplace of my maternal grandfather, Giuseppe Aiello. If you sit in the Piazza Castello in the late afternoon, you will watch the children of Ventotene take over the square with their games. They will play together, with parents and grandparents looking on, until midnight or later. It is a little oasis of youth and family and friendship and joy.

One evening I noticed a small group of children running and dancing about, and among them a little boy was limping. There was something wrong with his leg — perhaps a birth defect — but he was playing right along with his friends. “Andiamo,andiamo,” they shouted, and the little boy kept up with them. More than that, he was a vital part of the game.

We have forgotten what a remarkable thing this is: a little boy with a physical defect is included, accepted, and welcomed into the human family. We do not neglect him: we make room for him. This did not used to be a moral norm for Western Civilization — not before the arrival of Jesus the Nazarene and the emergence of his church.

We know what the Greeks, especially the Spartans, thought of babies and children who did not measure up to their physical ideal: they abandoned them and left them to die from the elements. The Greeks may have introduced democracy into the West, but their view of personhood was shallow and intolerant. Their cultural successors, the Romans, held ideas about human society that were equally impoverished. Romans were proud of their commitment to the rule of law (for Roman citizens), but their laws would not protect infants and children deemed useless to the regime. As declared in Rome’s The Twelve Tables: “Deformed infants shall be killed.”

These assumptions about “useful” human lives, according to historians, were “infamously universal” among the Greeks and Romans (as well as virtually every other ancient society). The philosopher Seneca admitted that “we drown children who at birth are weakly and abnormal.” Girls were at special risk. A letter from a pagan husband to his pregnant wife, dated at about the time of Jesus’s birth, captures the mindset: “if it is a boy keep it, if a girl, discard it.” Social scientist Rodney Stark writes that the exposure of infants was not only common, but “it was justified by law and advocated by philosophers.” W.E.H. Lecky called infanticide “one of the deepest stains of the ancient civilizations.”

Yet a profound change came over the West with the ascendance of the Christian sect in the centuries after the death of Jesus. A new ethos, based on a radically new outlook on human life, was introduced into the bloodstream of our culture. At its core was a belief that every individual — regardless of his or her status in society — was loved by the God of the universe.

Jesus himself set the example: the teacher who broke conventions and praised the humility of children as a gateway to achieving peace with God; the miracle worker who healed the lame, the lepers, and the blind; the preacher who enraged the religious establishment by insisting that no person — no matter how lost or despised — was beyond the reach of God’s grace. “What do you think?” he asked the crowds. “If a man owns a hundred sheep, and one of them wanders away, will he not leave the ninety-nine on the hills and go to look for the one that wandered off? And if he finds it, truly I tell you, he is happier about that one sheep than about the ninety-nine that did not wander off.”

Armed with this ethic, the early church vigorously opposed infanticide and became widely known for rescuing and caring for abandoned children. It was the Emperor Valentinian, under heavy Christian influence, who first outlawed these practices. Today’s legal regime against infanticide — simply taken for granted across the globe — must rank as one of Christianity’s greatest legacies.

But who among our educators, intellectuals, and entertainers is aware — or willing to admit — this legacy? We trumpet our progressive ideals, our culture of tolerance and inclusiveness, but forget where it all came from. We imagine that our ethos of compassion for the most vulnerable comes naturally, or that it can flourish without people of faith.

The secular republic teaches that we can dispense with the lives of the saints and yet preserve their hard-fought achievements. But history suggests that this belief is a leap into the dark, which no fireworks display can conceal.

Joseph Loconte is an associate professor of history at The King’s College in New York City and the author of God, Locke, and Liberty: The Struggle for Religious Freedom in the West (Lexington Press, 2014).