Pope emeritus Benedict XVI commemorated the centennial of the birth of Karol Wojtyła, who became Pope John Paul II, in an open letter to the Polish people addressed to Cardinal Stanisław Dziwisz, who was the longtime private secretary to the Polish pontiff.

A mix of emotional memoir and theological thoughts on the heritage of John Paul – who was born on May 18, 1920, and died April 2, 2005 – the letter is a call not to divide the Church within a line of pontificates, but see each pope as a continuity of his predecessor.

Benedict says John Paul marked a turning point in the history of the Church. After commenting on the turbulences that troubled both the world and the Church at the time of John Paul’s election, the pope emeritus says that “an almost impossible task was awaiting the new pope. Yet, from the first moment on, John Paul II aroused new enthusiasm for Christ and his Church.”

John Paul’s proclamation of “Do not be afraid” characterized his entire pontificate and – Benedict continues – “made him a liberating restorer of the Church.”

Before succeeding John Paul, the then-Cardinal Joseph Ratzinger was one of his closest collaborators for 27 years as the head of the Vatican’s doctrinal office. In his letter, Benedict compared his predecessor and successor, stressing “the inner unity of the message of John Paul II and the basic intentions of Pope Francis can also be found: John Paul II is not the moral rigorist as some have partially portrayed him.” It is the opposite, Benedict writes: “With the centrality of divine mercy, he gives us the opportunity to accept moral requirement for man, even if we can never fully meet it.”

Polish theologian and John Paul II expert Dominican Father Jarosław Kupczak told Crux the letter “is like a sip of spring water,” adding it is a gift not only to the Polish nation, but to the world.

“We see today various attempts to divide the modern papacies along different lines that serve the current interests of different factions. There is no theological break between John Paul II and Benedict XVI, neither is it between John Paul II and Francis,” Kupczak said, “because the teaching of the Church should be read in accordance with the hermeneutic of continuity, not rupture.”

The 93-year old pope emeritus explained the love of Divine Mercy by John Paul II with a personal story on how respectful he was with his collaborators.

John Paul was deeply touched by the message of Faustina Kowalska, a nun from Kraków, who emphasized Divine Mercy as an essential center of the Christian faith. Because of that, he wanted to establish a feast day for Divine Mercy. The pope consulted the Congregation for the Doctrine of the Faith on whether it could be the second Sunday of Easter.

The Congregation, led by Ratzinger, answered twice with a negative response, explaining that Sunday is “in Albis” and set aside for the Easter Octave, according to an ancient tradition. John Paul accepted the “no” and changed his proposal so that it respected the historical meaning, but also included the Divine Mercy.

“I was impressed by the humility of this great pope, who abandoned ideas he cherished because he could not find the approval of the official organs that must be asked according established norms,” Benedict writes.

In another part of the letter, Benedict remembers when John Paul passed way: “I cannot forget the moment when Archbishop Sandri announced the message of the pope’s departure. Above all, the moment when the great bell of St. Peter’s took up this message remains unforgettable.”

Benedict also wrote about the discussions about calling John Paul “the Great” after his death and pointing out that only two popes were given that honor, Leo I in the fifth century and Gregory in the sixth century: He said John Paul was in that league.

“The similarity is unmistakable,” he writes. John Paul courageously confronted a strong civil power the same way as the other two popes, and nevertheless he won over the tyranny.

“The power of faith turned out to be a force that finally unhinged the Soviet power system in 1989 and made a new beginning possible. Undisputedly, the pope’s faith was an essential element in the collapse of the powers. And so, the greatness that appeared in Leo I and Gregory I is certainly also visible here.”

Pope Francis is scheduled to celebrate his 7 a.m. morning Mass on May 18 at the tomb of John Paul II. It will be livestreamed by Vatican media.

At 8 p.m. the same evening, Francis’s remarks for the centenary of John Paul’s birth will be livestreamed by the Archdiocese of Krakow and be aired on Polish television.