The Catholic Church’s consecration of Russia and Ukraine to the Immaculate Heart of Mary on Friday is a radical call to personal, ecclesial, and social conversion, a Vatican cardinal has said.

“I think that, beyond the specific form of a gesture, the Lord, and with him the Blessed Virgin Mary, look at the substance, the truth of the gesture and the spirit,” Cardinal Mauro Piacenza, the head of the Vatican’s Apostolic Penitentiary, said about the consecration.

In a March 25 interview with ACI Stampa, CNA’s Italian partner agency, Piacenza said that “for our part, as men on the road, every act of consecration is — and must be — a radical call to personal, ecclesial and social conversion.”

The act of consecration, which the pope has asked the world’s bishops and Catholics to join in, will take place in St. Peter’s Basilica after a penitential service which begins at 5 p.m. Rome time. The consecration will take the form of a prayer invoking Mary’s intercession for the gift of peace.

Peace, the penitentiary major said, “is intimately linked to mercy. Inner peace, the peace of the heart, the peace of the conscience of each person depends on divine mercy, on the awareness that one’s own contradictions and sins can find a solution only in the embrace of the Father’s love.”

“There is no peace without justice and there is no peace without mercy,” he said. “Therefore, the link between peace and mercy is deeply rooted in the very will of God, which must increasingly become the will of men: learning mercy towards one another, following the example of a merciful Father, is the necessary prerequisite for peace among nations as well.”

Piacenza said he was certain that the prayer of consecration would have an effect on the world tensions caused by the Russia-Ukraine war, though it might not be measurable by human criteria.

“It is not for us men to measure the power of Marian intercession for divine mercy,” he said, adding that “certainly, consecration to the Immaculate Heart of Mary does not remove man from his responsibilities and from a use of freedom consistent with truth and good.”

But if done well, prayer has enormous power, he said, “such that we can say with St. Bernard that the intercession of the Mother of God has the characteristics of ‘supplicating omnipotence.’”

The 77-year-old Italian cardinal repeated that “the consecration will have its own efficacy which, although not measurable by purely human criteria, will also be able to change the course of events in history, certain that, as the Blessed Virgin Mary herself has promised, her Immaculate Heart will triumph.”

“In the end, it will triumph,” he added. “And it will be the triumph of divine mercy.”