With the simultaneous canonizations of his predecessors, Pope Francis has not hesitated to slightly bypass canonization procedures by not waiting for confirmation of a second miracle attributable to Pope St. John XXIII.

And this was most certainly the right course to take.

St. John XXIII and St. John Paul II are, of course, very different from each other, but they also have many things in common. Without John XXIII, it is possible to suggest that there would not have been a John Paul II. Their canonizations bear witness to the fact that the Church is a compagnia semper reformanda (enterprise always to be reformed), as Pope Emeritus Benedict XVI used to stress. At the same time, it shows that every piece in the history of this enterprise is linked to others, like pieces fitting in a puzzle.

What do the two men who were canonized together April 27 have in common? First of all, they have both been popes — saintly popes. They profoundly lived out their priestly spirituality, as their episcopal mottos show. John XXIII had chosen " Oboedientia et Pax" (Obedience and Peace); John Paul II chose "Totus Tuus" (Totally Yours), an affirmation of total trust in the Virgin Mary.

Their life stories are vastly different. John Paul II had lost his mother before his first Communion and his father at the age of 21, and he lived his priestly vocation as a parish priest and then a bishop in war-torn Poland. John XXIII was raised in a large family and was sent by the Holy See to Turkey, Bulgaria and France as pontifical legate and apostolic nuncio. His diplomatic work forged his faith and vision of the Church, a Church that is inclusive, ecumenical and in dialogue with the world.

His homily at the Pentecost Mass in Turkey in 1944, his last there, before leaving for France, is a vivid example of Angelo Giuseppe Roncalli’s thought. He said that Christians in all confessional groups loved to make a distinction between themselves and those who do not profess their faith, be they "the Orthodox, Protestants, Jews, Muslims, believers and nonbelievers." But, he continued, even if "diversity in races, language, education or the painful differences of a sad past keep us at a distance from each other, under the light of the Gospel, we see that Christ has come to tear down walls; he died to proclaim our universal fraternity; the center of this teaching is the love that links every man to him as the first of brothers, and that links him and us to the Father."

"Tear down walls": These words are the marching orders that, more than anything else, bind together the two saintly men. The ecumenical effort was vigorously pushed forward by John Paul II, who, going beyond diplomacy, embraced prophetical gestures in dealing with the politics of religions.

When he went to Greece in 2001, the first pope to go there in 1,291 years, he listened calmly to a list of accusations (13 offenses) levied against the Catholic Church by the Greek Orthodox. Then, he apologized for errors that had been made. Finally, during a historic meeting at the Areopagus, he affirmed with Greek Orthodox Archbishop Christodoulos of Athens their common commitment to defend the Christian roots of Europe. After that, he broke the taboo of Orthodox and Catholics praying together, reciting the Our Father with the Greek archbishop.

John XXIII had already begun to tear down the invisible wall of the Iron Curtain when the Soviet Union experienced its first cracks. In 1961, the then-secretary of the Russian Communist Party, Nikita Krushchev, made a first move to establish communications with the pope, sending a best-wishes message to John XXIII for his 80th birthday.

John responded, and a channel of informal contact was thus opened. When the Cuban Missile Crisis broke out in 1962, John XXIII was the only moral authority recognized by the two opposing sides. The pope’s public remarks — which he rewrote almost in their entirety — in the midst of the crisis were even published in Pravda, the Soviet Union’s propaganda newspaper. The crisis was thus overcome.

The outcome of that initiative convinced John XXIII to write an encyclical, Pacem in Terris (Peace on Earth). The encyclical — built on truth, justice, freedom and love as its four pillars — was John XXIII’s utopian goal.

John wanted the encyclical to be written in an innovative way. The document has as its foundation the signs of the times, men’s longing for dignity, freedom and peace.

From this perspective, the whole of human aspirations are read in the light of the Gospel, and efforts for their realization constitute the pursuit of that integral humanism that would become Paul VI’s marching orders.

For the first time, an encyclical took as its starting point not Revelation, but the signs of the times. This inductive method was then applied in the Second Vatican Council’s Pastoral Constitution on the Church in the Modern World, Gaudium et Spes.

The aura of Pacem in Terris also captivated a young bishop taking part in the Second Vatican Council, Karol Wojtyla. He had experienced Nazism and communism, two forms of totalitarianism that had shaken Europe. His opposition to all forms of totalitarianism led to a particularly strong stance against communist regimes. He opposed them not through direct protests or a frontal attack. Instead, he nurtured young people, educating them on what freedom is and what human dignity means. It was humanism saving the world.

Archbishop Wojtyla was one of the most active drafters of the conciliar document Dignitatis Humanae (The Right of the Person and of Communities to Social and Civil Freedom in Matters Religious). The declaration on religious freedom was an incredibly valuable tool for all the bishops on the other side of the Iron Curtain, who took inspiration from it to form a silent opposition. He linked the defense of human dignity to the notion of "nation," which he leveraged in contrast to the notion of "state."

In the meantime, the so-called Vatican ostpolitk had begun. Cardinal Agostino Casaroli was sent to countries on the other side of the Iron Curtain first by John XXIII and later by Paul VI.

Once elected pope, John Paul II chose Cardinal Casaroli as secretary of state. The pope’s strong stance on freedom and human dignity stirred the aspirations of those living in countries of the Warsaw Pact. At the same time, Cardinal Casaroli’s diplomacy kept active relations with communist countries, affording the pope’s position some protective coverage.

On one side were John Paul II’s stances, and on the other was Cardinal Casaroli’s shrewd diplomacy; and in the background was a behind-the-scenes cultural dialogue. This is how the Berlin Wall was eventually torn down. The images of the fall of the Wall represent the fall of European communism and a triumph for Catholics.

Had there not been a John XXIII, none of this would have been possible. He laid the groundwork for the Holy See’s influence to increase considerably in the international arena. He who had been called the "Shepherd Pope" was in fact a fine diplomat.

John Paul II embraced this legacy. He challenged the United Nations often, speaking about religious freedom at the U.N. headquarters in New York and also criticizing the "gender ideology" and the notion of "reproductive health" of the Cairo and Beijing conferences during the 1990s.

Ultimately, John XXIII and John Paul II followed the same method, comprised of dialogue with the world and action. John Paul II, recounting in an off-the-cuff remark how the idea of World Youth Day came up, showed how this method was carried out: "It was 1984, and a big friend of ours, the United Nations, established a Year for the Youth. They made announcements; they made plans. We did it!"

This spontaneity tore down walls. John XXIII opened a window of the Church into the Second Vatican Council by airing out the window of the Apostolic Palace on Oct. 11, 1963, and pronouncing his famous "sermon of the moon," asking people to "hug their children."

John Paul II offered a glimpse of what to expect from his pontificate in the Mass beginning his Petrine ministry: "Open wide the doors for Christ. To his saving power the boundaries of states, economic and political systems, the vast fields of culture, civilization and development open. Do not be afraid. Christ knows ‘what is in man.’ He alone knows it."

Andrea Gagliarducci is the Vatican observer for CNA/EWTN News. He writes from Rome.