When immediately after his election he appeared on the balcony of St. Peter’s Basilica before an immense crowd, his rotund appearance struck a great contrast with his predecessor, the slender and dignified Pius XII. It soon became known, moreover, that unlike the circumspect and reserved Pius, John was spontaneous. Here was a pope who liked to tell jokes!

John’s next surprise came three months after he was elected, when he announced the Second Vatican Council. Not only was the council unexpected, but so was John’s decision to invite representatives of other Christian churches to attend. In fact, “Good Pope John” seemed to be full of surprises. But if we look at the years he spent as a priest and bishop, we will see that none of his unexpected moves were really all that surprising. Rather, we see how God used his unique life story to form Angelo Roncalli into the man who would usher in a new era for the Church.

A Transparent Soul. On the day the council opened, October 11, 1962, Pope John asked the bishops to show the Church to be “benign, patient, full of goodness and mercy.” For many people, John seemed to embody this image of the Church: a man whose heart was open to everyone. John himself was benign, patient, and full of goodness and mercy.

We can see these qualities in two unique facts about John XXIII. First, he is the first pope in history from whom we have a personal diary that extends over his entire adult life. For decades, he kept a spiritual journal, an ongoing record of his closeness to the Lord and his long internal pilgrimage toward holiness. Excerpts, entitled Journal of a Soul, were published in multiple languages in 1965, and the book continues to nourish the souls of millions around the world. An entry as early as 1902, when he was a seminarian in Rome, reveals much about his heart: “Lord, I need only one thing in this world: to know myself and to love you.”

Second, John is the first pope in history who has left us a collection of letters written to his family from the time he was a teenaged seminarian until the year he died. As a result, we know more about John the person than we know about any other pope.

A Friendly Ambassador. With the exception of Pope Pius X, the popes of recent centuries had all come from noble, or at least well-placed families. But Angelo Roncalli was born into a large family of peasants in a little village in northern Italy. But he was not destined to remain a simple country priest. On the contrary, his vocation took him to a wide variety of people and places, giving him a breadth of experience greater than any of his predecessors.

When World War I broke out, Padre Roncalli served in the Italian army, first as a hospital orderly and then, in military uniform, as a chaplain. Thrust into the chaos of war, he found himself surrounded by men who were very different from the priests he had lived with since he was a boy. He came to know these soldiers well and gradually began to appreciate the goodness lying under their cursing and occasional bad behavior. His time in the military, ministering to shell-shocked young men, helped him develop the capacity for patient and respectful listening that would become his hallmark.

That talent for listening achieved a new breadth a few years after the war, when Pope Pius XI made him an archbishop and sent him as apostolic delegate to the predominantly Orthodox country of Bulgaria. The Catholic population there was small, poor, and marginalized, and that made his time there difficult. “My heart breaks,” he wrote. “We do not even have oil to light the lamps in the chicken coops we use as chapels.” But his main job was to make the Catholic Church known to the leaders of the Orthodox Church. He was to minister not only to ordinary people but to Church leaders like himself. And once more, he learned that friendliness and respectful listening could carry him a long way.

For the next ten years, he held the same position for Greece and Turkey. During that time he lived in Istanbul, capital of an Islamic country that was busy rejecting all religion as outmoded. This fact made it difficult for Roncalli to establish good relations with Turkish authorities. But he had hardly arrived before he wrote in his diary, “I am fond of the Turks, to whom the Lord has sent me.”

His fondness bore fruit in March 1939, when he celebrated a thanksgiving service in honor of the newly elected pope, Pius XII—in the company of the Orthodox patriarch of Constantinople! When Roncalli went to thank him some time later, the patriarch embraced him warmly. The gesture had great symbolic significance, considering the enmity that had lasted for centuries between the church of Rome and the church of Constantinople (present-day Istanbul). Again, his open heart, his friendliness, and his simplicity won people over.

A Wartime Pastor. Meanwhile, World War II broke out. On the very day that Germany invaded Poland, Roncalli went to work organizing relief for Polish refugees. Two years later, in an effort to relieve the famine that had stricken occupied Greece, he met secretly with the Orthodox metropolitan (archbishop) of Athens. Describing the two-hour meeting later, Roncalli said, “We began with a handshake, but we said farewell with an embrace and with sincere joy in our hearts.”

In 1944, he had two meetings with Isaac Herzog, chief rabbi of Jerusalem, over efforts to save a large group of Jewish refugees. Roncalli could not do much, but he did what he could. In response, Herzog offered “my deepest gratitude for the steps you have taken.” Then, seeming to capture Roncalli’s personality in just a few words, he said, “You follow the noble feelings of your own heart.”

Many years later, just a few days after the opening of Vatican II, Roncalli, now Pope John XXIII, met with the leaders of the other Christian churches who were the council’s guests. These “observers,” as they were officially called, consisted not only of Protestants but of several Orthodox patriarchs. John recalled his earlier contacts with non-Catholic leaders. “Never, to my recollection, was there among us any muddling of principles. . . . We did not negotiate; we talked. We did not debate but loved one another.”

A Quiet Diplomat. In 1944, after twenty years of living outside western Europe, Roncalli faced another challenge. Pius XII named him nuncio to Paris, traditionally the Vatican’s most prestigious diplomatic post but certainly not a plum in 1944.

Roncalli was thrust into another difficult situation. The Allies had just liberated the city from the Nazis. General Charles de Gaulle was the country’s new leader. Devout Catholic though he was, he demanded that the Vatican remove some twenty-five bishops who were accused of cooperating with the Nazis. Although Roncalli cannot be given credit for the solution in which seven bishops quietly left office, he acquitted himself well in this explosive situation and earned the respect of high and low during his nine years in France.

In 1953, Pope Pius XII made Archbishop Roncalli a cardinal and named him patriarch (bishop) of Venice, where he won the affection of his flock almost immediately. When Pius died in 1958, Cardinal Roncalli wrote in his diary just before leaving for Rome, “We are not on earth to be museum keepers but to cultivate a flourishing garden of life.” A few days later, to his surprise and to the surprise of the whole world, he was Pope John XXIII. He was in a new position to cultivate that garden.

A Big Warm Heart. History will remember John XXIII as the pope who opened Vatican Council II in October of 1962. John died of stomach cancer after the council’s first year, but his voice continued to echo throughout the council’s remaining three years. In insisting on dialogue as a way of coming to mutual understanding and of reducing hatred and bigotry, the council fathers could not have hit on a program that better reflected John’s hopes for it.

John XXIII engaged with other people, as the Church must do. He listened to them and learned from them, as all believers must do. And as he listened and learned, his big heart grew ever bigger and more encompassing, as we must do.

Pope John’s death on June 3, 1963, evoked a worldwide outpouring of grief that had never before occurred for a pope. People saw in his death the loss of a great leader, but many also felt it as the loss of a personal friend, of somebody who understood them, who could sit around their kitchen table and tell jokes, and whose heart was warm. For them he was the living embodiment of a person loving toward all, benign, patient, full of goodness and mercy.

John O’Malley, a well-known Vatican II scholar, is a Jesuit priest and professor at Georgetown University, Washington, D.C.