(CNN) — This Sunday, Pope Francis will canonize “Good” Pope John and Pope John Paul “the Great.”
These popular references to Pope John XXIII and Pope John Paul II recall the ancient practice of choosing saints by public acclaim.
Sunday’s ceremony, on the other hand, is the result of a more elaborate process and a brilliant decision by their successor, Pope Francis.
Though they will be canonized together, in some ways these two popes were very different people.
Angelo Giuseppe Roncalli was one of 14 children from an Italian peasant family who became a historian, diplomat, bishop and then Pope John XXIII.
Long before Pope Francis’ off-script, populist touches led some to dub him the “people’s pope,” John broke precedent by escaping the Vatican to visit hospitals and prisons.
He left as a legacy his encyclical “Pacem in Terris,” which was addressed for the first time not just to Catholics, but to all those of “good will.” It reshaped Catholic teaching on human rights and made an impassioned call for peace amid the Cold War.
Though John XXIII served for only five years (1958-1963), he forever changed the church by convening the Second Vatican Council, which reformed Catholic liturgy, interfaith relations and the church’s approach to the modern world.
Karol Józef Wojtyła was the third child of a captain in the Polish Army. He was an actor, athlete, philosopher and theologian who became a bishop, cardinal and then the first non-Italian Pope in centuries, Pope John Paul II.
As Pope, he did not just write to “people of good will,” he traveled to 129 countries to meet and speak to millions of them. His encyclicals reaffirmed and enriched Catholic teaching on work and labor, solidarity and the market, human life and the search for truth.
He served five times longer than Pope John, for more than a quarter century. He changed the world with his courage in standing with the workers of Solidarity and the Polish people against Soviet domination and Communist repression. That nonviolent resistance was the beginning of the demise of the Soviet Union and the end of the Cold War.
John Paul II, from the first moment of his papacy, said “do not be afraid.” Likewise, John XXIII was unafraid of opening the windows of the church to the modern world.
Both men called for the church to engage modern times and not to turn inward to simply preserve and protect its ideas and traditions.
The world took notice.
Pope Francis was not the first Pope to be Time magazine’s “person of the year.” Both John XXIII and John Paul II were recognized on the cover of Time’s year end issues.
But, even in the midst of this celebration of the holiness and leadership of these two popes, it would be a mistake to ignore the challenges and shortcomings of the church and its leaders.
Catholics sharply disagree on the how the Second Vatican Council’s reforms have been implemented, on the way authority is exercised, on the role of women in the church and on matters of human sexuality.
Clearly, John Paul II’s legacy is scarred by his inattention and inaction on the clerical sexual abuse crisis, and the whole church is haunted by this terrible failure.
Pope Francis is trying to address these challenges and is calling on Catholics to refocus on fundamentals: On God’s love and mercy, on our duty to love and defend the poor, the vulnerable, the very young and very old and those left behind by an economy of exclusion and injustice.
The genius of the twin canonizations is that they bridge generations, church divisions and different visions of holiness and greatness.
A progressive urban pastor can smile at the memory and hopes that came with John XXIII.
At the same time, the “JPII generation” of younger, more conservative priests can celebrate the strong leadership that called them to serve the church.
Lay men and women can recall that John XXIII and John Paul II called them to greater responsibility in the church and in sharing the Gospel and Catholic teaching in the world.
For Catholics, this is a time to honor John XXIII’s humanity, holiness and call for renewal and John Paul’s strength and courage in facing prolonged illness and in standing with workers and for freedom in Poland.
By canonizing them together, Pope Francis avoids the danger of lifting up one way of leading the church as the only way to guide the Catholic family of faith.
Their differing histories, personalities, strengths, weaknesses and legacies can help Catholics appreciate legitimate differences within the one body of Christ.
If both Pope John and Pope John Paul can be made saints on the same day, maybe Catholics can be more respectful of differing perspectives and priorities in today’s church.
On Sunday, there may be cheers from different parts of the crowd in Saint Peter’s Square at different moments.
However, we are one family of faith, united by a common Gospel, consistent teaching and the complementary legacies of these two “fathers” we call “holy” in a new way.
John Carr is director of the Initiative on Catholic Social Thought and Public Life at Georgetown University. He previously served for more than two decades as the director of justice and peace efforts of the United States Conference of Catholic Bishops. The views expressed in this column belong to Carr.
Opinion by John Carr, special to CNN
™ & © 2014 Cable News Network, Inc., a Time Warner Company. All rights reserved.