On February 24, 2005, on a cold, rainy day, 40,000 people descended on the cathedral square of Milan, Italy. About 10,000 of them squeezed into the cathedral itself where a funeral was being held. The rest remained in the square, watching the service on large screen monitors. Television cameras and crews covered the event "live."

The deceased was not a former prime minister, opera star, soccer champion, or even a cardinal or archbishop. The funeral was merely for a priest named Luigi Giussani. There to preach the homily was one of the highest ranking officials in the Roman Catholic Church, none other than Cardinal Joseph Ratzinger, who had personally begged the ailing Pope John Paul II to be given the honour. In a little over a year, Ratzinger would himself become Pope.

Who was this priest who merited such an outpouring of love and devotion, and why should anyone in North America, Catholic or non-Catholic, care?

The answers to those questions concern everyone who cares about the health and influence of the Christian faith in the twenty-first century and beyond.

But to reach those answers, we must go back to another day in Italy, this one in 1953, where the thirty-one year old Father Giussani was riding a train, chatting casually with some high school students. The ravages of World War II were still visible in the countryside, but peace and prosperity offered hope for the future. As a priest in a thoroughly Catholic country, Father Giussani was treated with great respect by young and old alike. The Church was still a dominant presence in society. Everyone attended Mass and was baptized, confirmed, married, and buried within the Catholic faith.

And yet by the end of that train ride, and that conversation with the students, Father Giussani had the unshakeable conviction that the whole edifice of faith was about to collapse in a heap of shattered fragments. It wasn't that the students were openly rebellious or disrespectful—they weren't. It was just that Father Giussani detected no real sense that they understood their faith, or experienced it as something real and sustaining in their lives.

So he did something about it—something quite radical. He resigned his position as a professor at a prestigious seminary and enrolled as a high school teacher in the centre of Milan. He proved to be such a provocative teacher that students began to hang out with Father Giussani after school.

What was so provocative about his teaching method? For one thing, students were not accustomed to learning about God by studying the work of the Romantic poet, Giacomo Leopardi.

For another, Giussani's understanding of the essence of Christianity did not seem to tally with what the young had assumed it was. They thought the faith was about following rules and regulations, about grand, abstract ideas spouted by ancient philosophers. Above all, they thought Christianity was telling them that their deepest desires were inherently wrong and had to be suppressed.

The heart of Giussani's message is that Christian faith is not fundamentally about morality or ideas. Instead, he said:

Christianity is an event. There is no other word to indicate its nature: neither the word law nor the word ideology, conception, or project. Christianity is not a religious doctrine, a series of moral laws, a complex of rites. Christianity is a fact, an event: everything else is a consequence. (in Un avvenimento di vita, cioè una storia, 1993)

Going back to the Gospels, Giussani pointed out the way that the disciples first met Jesus. Hearing Jesus speak was an encounter, a collision of one human presence with another. So powerful was this encounter that it became an event in the lives of those who experienced it.

Giussani noted that most people skip past this encounter and immediately make Christ an abstract teacher or law-giver. But to do this is to live inside our heads, and to ignore the reality of our hearts. Again and again, Giussani emphasized that Jesus came to awaken our humanity, not turn us into mere followers of an ideology.

And that's where another of his strange notions entered in. Giussani actually praised desire, told the young, hormonal kids around him that the desires of the heart are not fundamentally evil. Our desire for love, justice, truth, and beauty is based on the original design of our natures—a design God intended. Christianity, he said, came not to abolish desire, but to align our desires with their ultimate goal: not mere passing pleasures, but the infinite itself.

Giussani's approach was deeply indebted to the vision of Augustine of Hippo, whose Confessions affirm the goodness of human desire. Yet for some in the Church of his day, Giussani's Augustinian approach was far too "existential," too preoccupied with experience and insufficiently grounded in propositions and laws.

In the atmosphere of the late 1950s and early 1960s, Giussani's approach seemed dangerous. For one thing, gatherings of Catholic students were supposed to be separated by gender. Giussani took the daring approach of having young men and women in the same room with one another. He was even briefly exiled to San Antonio, Texas, for his risqué tactics before being allowed to continue his work.

Ironically, Giussani's prophetic instinct, the sense he had on the train on that day in 1953—that Italian Catholics were merely following customs and habits without any real engagement with faith—was proved true during the upheaval of the 1960s and especially during the campus riots of 1968. Politics had replaced religion in the hearts of the young as the source of ultimate meaning.

At that time even many of his followers decided that Marxism was preferable to Christianity and his community was torn apart. Those who followed Giussani in remaining focused on faith as prior to political action were often threatened with violence.

Out of the ashes of that time—a time when millions of Italians left the Church altogether— rose another phase of Giussani's movement. It took the odd name of "Communion and Liberation," seeking to recover a Christian word that had been taken over by the Marxists.

Communion and Liberation stood out from many other religious organizations, then and now. Instead of dwelling on pious topics and retreating to the safety of a subculture, Communion and Liberation tended to sponsor lectures and conferences on broad human questions of art, politics, and the sciences. They lived fully and vibrantly in the public square.

Another distinctive of the Communion and Liberation community was Giussani's emphasis on friendship or, as he put it, "companionship." He pointed to the example of the disciples after the Passion and Resurrection of Christ. As recounted in Acts, they were to be seen on a daily basis under Solomon's Portico, talking earnestly among themselves about the meaning of the encounter they had. They remained with one another.

Thus was born the idea of a movement, a sense of belonging to a shared experience of the encounter. Giussani insisted that he never intended to found a movement, and he went on to say that a movement is not an exclusive club, but merely a way of recreating the unity and intensity of what the first apostles lived.

And so Communion and Liberation members came to meet every week at what is known as the School of Community. They also took vacations together, characterized by lots of vigorous singing, hiking, and game-playing. To the astonishment of those who visit every major Communion and Liberation event, the very last thing that takes place at such occasions is known as the "Frizzi," in which all the serious presentations are mercilessly mocked in a series of hilarious comic sketches. Giussani, known to be a fan of the writings of G. K. Chesterton, might have thought up the Frizzi when he read Chesterton's quote: "Angels can fly because they take themselves lightly."

Communion and Liberation began to grow rapidly and was officially recognized by the Vatican in 1982. It is, of course, only one of dozens of lay movements that have sprung up in the Catholic church in the last half century. It now numbers over 60,000 members spread across the globe. It is even gaining adherents in highly individualistic North America, with communities in most major cities in the United States and Canada. Each August, Communion and Liberation holds a weeklong event in Rimini that brings hundreds of thousands from all over. Known simply as "The Meeting," it has featured leading figures from politics, science, and the arts, including Lech Walesa, Supreme Court Justice Samuel Alito, and the late Russian film director, Andrei Tarkovsky.

The influence of Giussani and Communion and Liberation continues to grow, even after his death. Pope John Paul II was a profound admirer, but Joseph Ratzinger was even more deeply engrossed in Giussani's vision of the world. In his first encyclical, Pope Benedict XVI begins by writing: "Being Christian is not the result of an ethical choice or a lofty idea, but the encounter with an event, a person, which gives life a new horizon and a decisive direction."

At Giussani's funeral, then-Cardinal Ratzinger said that Giussani "understood that Christianity is not an intellectual system, a packet of dogmas, a moralism; Christianity is rather an encounter, a love story; it is an event."

The current pope has expressed his affection for Communion and Liberation in a very tangible way. Benedict's papal household is run by a group of Communion and Liberation members from the group known as Memores Domini. These are individuals who have chosen to live what Catholics call the "evangelical counsels"—poverty, chastity, and obedience. But Memores Domini do not live in monasteries; they live in the midst of the workaday world, holding ordinary jobs.

Communion and Liberation, guided by the wisdom of Father Giussani, holds out a compelling model for Christian engagement with both church and world. It is a model that eschews politics and ideology, preferring to share a passion for beauty over endless culture wars.

Certainly the majority of those in attendance at Father Giussani's funeral in Milan were Italian. But there in the throng were several dozen from Montreal and Toronto, New York and Los Angeles, and smaller places, such as Evansville, Indiana. They were all there because of a man who knew that faith is an encounter with a presence, a presence that can make us truly human and better able to relate to the humanity of those around us.