The great-nephew of Blessed John XXIII revealed the pontiff's Church vision in calling for the Second Vatican Council, noting the great continuity between his ideas and the pontificate of John Paul II.

"John XXIII does not avoid confrontation with the world of his time, although perhaps the real dialectical confrontation with modernity was up to Paul VI," Marco Roncalli told CNA, "however it is Pope (John XXIII) Roncalli that opens the council and opens wide the windows and the doors of the Vatican."

"He has a vision of a Church like a garden, not like a museum...like a fountain in the village that offers to quench everyone's thirst," Roncalli said in an April 22 interview.

"John Paul II takes up this legacy (and) continues to recognize that the council is the compass of our time."

In addition to being a relative of the soon-to-be saint, Roncalli is the president of the John XXIII Foundation and author of "Giovanni XXIII – Angelo Giuseppe Roncalli: A Life in History."

He is also the editor of correspondences from 1933-1962 between John XXIII, his secretary Loris Francesco Capovilla, and his close friend Giuseppe De Luca.

Much of John XXIII's pontifical legacy can be seen in the Second Vatican Council, also known as Vatican II, which he opened in 1962 and was closed in 1965 under Pope Paul VI. Future Popes John Paul I, John Paul II and Benedict XVI were also present throughout the council and participated in its discussions.

The council gave particular focus to the Church's relation to the modern world and implemented a number of reforms designed to make the teachings of the Church more understandable without compromising their content.

Roncalli noted the continuity between both John XXIII and John Paul II in their understanding of and commitment to the values espoused by Vatican II.

Even if they had "very different sensibilities," both pontiffs each believed strongly "in the dignity of the human person, social justice, mercy," he said.

Roncalli observed that although at first not everyone was a fan of coupling John XXIII's canonization alongside that of John Paul II, he now thinks many believe that if "John Paul is the Great, the other one will not be less."

Referring to his uncle's immense spiritual life, Roncalli affirmed that the Pope was "a man of faith as strong as a rock, a man who loved even those who opposed him, relying on God," and "approaching all in the pursuit of what could unite and not divide."

He was "a man who has always placed the Gospel before any personal affirmation" and "has left us with a public example of holiness" and "repeatedly told us to not be afraid of modern times."

John XXIII has also "asked us to learn how to read the signs of the times," he continued, observing that the Pope "explained to us the irrationality of any conflict" and "told us that the lack of unity among Christians is a scandal."

Of his decision to convene the Second Vatican Council, the pontiff's great-nephew explained that it came as a result of the saint's intense spiritual life.

"John began right away with a profound reflection on the situation of the Church immediately after his election," he noted, stating that it was a "conviction already set in his spirit, comforted in prayer, transformed into personal decision and irrevocable, right after recording the positive opinion of the Cardinal Secretary of State, Domenico Tardini."

It was only after receiving "the certainty that at the root of his idea there was truly a moment of grace" that the pontiff brought up the idea, Roncalli continued.

Quoting something his great-uncle had written about the calling of the council, Roncalli said that "it was not about 'passing fantasy, or spectacular improvisation,' but of 'an inspiration' that obliged him to 'submit himself, as ever, to the will of God.'"

Later on Pope John explained "that the idea of the Council came not 'as the fruit of a prolonged meditation, but as the spontaneous flower of an unexpected spring,'" he noted.

Roncalli recalled that afterwards the pontiff applied to himself "the spiritual rule 'of absolute simplicity to welcome the divine inspirations and a prompt submission to the apostolic demands of the hour.'"

"This is part of his history of holiness – St. John – because in his life he continued to detach himself from himself, to put his 'I' under his feet, placing before all the Gospel to all and not concerned about anything but the Gospel."

"In this way that holiness which is now fully recognized by the Church emerged, to which he aspired every day," Roncalli noted, highlighting that his "holiness was private as (it was) public. Which Pope Francis has understood."

"The hermeneutical key to understanding well the figure of Angelo Giuseppe Roncalli…is precisely this of the spirituality absorbed by him during his adolescence and then regenerated in the ordinariness of every experience, primarily as a trust in God and in man, his image," the Pope's great-nephew continued.

Emphasizing that this "spirituality pervades and even ties decisions and writing without limits of public or private spheres," Roncalli observed that it is also revealed in his "highest exercises of the governance of the Church."

Pope John kept himself "always with God and with the things of God," the relative went on, affirming that he was "aware of being a man within a great family which is that of the human race and where fraternity that raises bridges and wishes to demolish barriers, as Christianity demands."

"Every saint is a success of God," he reflected, adding that "the power of grace that is almost surpassed by the nature of John XXIII is an appeal to us for continuous renewal, to be shaped by God."