ROME— As the Catholic church in Australia struggles with fresh revelations that some 4,400 people have reported being sexually abused in more than 1,000 Catholic institutions, a new book by a religious sexual abuse survivor with a preface by Pope Francis was revealed on Monday, in which the pontiff calls sexual abuse an “absolute monstrosity, a horrible sin.”

“For those who have been victims of a pedophile, it is difficult to talk about what they have been through and describe the trauma that persists still, after many years,” Francis wrote. “For this reason, Daniel Pittet’s testimony is necessary, treasured and courageous.”

The pope is talking about a 57-year old Swiss man, who was first abused at the age of eight by a Capuchin brother, who would continue molesting him for four years.

As Francis writes in the preface to I forgive you, Father, to be released in Italian later this month, he met Pittet in the Vatican back in 2015 during the Year for Consecrated Life. The pope’s words were released in full on Monday by the Italian newspaper La Stampa.

Pittet was at the Vatican to present a previous book, To love is to give everything, in which he collected the testimonies of religious men and women, priests and consecrated persons.

“I could not have imagined that this enthusiastic and passionate Christian man had been the victim of abuse by a priest,” Francis wrote.

When meeting the author, today a married man, a father of six and a librarian, the pope saw once again “the tremendous damage” caused by sexual abuse and the painful road that awaits the victims.

“How can a priest at the service of Christ and his Church cause so much harm?” Francis asks. How can someone devoted to leading children to God, end up “devouring” them in what the pontiff called “a diabolical sacrifice” that destroys the victim and the life of the Church.

“Some of the victims have been driven to suicide,” the pope acknowledges. “These deaths weigh on my heart, on my conscience and that of the whole Church. To their families, I offer my feelings of love and pain and humbly, I ask forgiveness.”

The Church, the pontiff wrote, citing a document released by the Vatican on June 2016, has the duty of being “extremely strict” with the priests who betray their mission and with the bishops or cardinals who might protect them.

Pittet, the pope writes, was also able to display “another face of the Church,” one which allowed him not to lose hope in men and God, with prayer comforting him in the “darkest hours.”

Last year, the man met with Joel Allaz, the Capuchin who abused him hundreds of times. Their conversation, in an interview format, is at the end of the book for which the pope contributes the prologue. Pittet, who for a while was a monk himself, writes about having forgiven his abuser and being able to build his life on that forgiveness.

“Many people fail to understand the fact that I do not hate him,” Pittet writes, and the pope quotes him.

Francis doesn’t attempt to deny just how big the scope of clerical sexual abuse is, thanking instead the book’s author because it is witness such as the one by Pittet that “break down the wall of silence that covered the scandals and suffering, shedding light on a terrible dark area in the life of the Church.”

Speaking to La Stampa, the Swiss man says the pope had insisted on wanting to know where the strength for his missionary spirit came from. Pittet first avoided answering the question, but when the pope wouldn’t back down, he eventually told Francis the truth: “Father, I was raped by a priest.”

“He looked at me in silence with tears in his eyes and hugged me,” Pittet said. “Now these are [Francis’s] strong and courageous words of condemnation of pedophilia, the secret that kills.”

He also told the Italian daily that having forgiven his abuser doesn’t mean he’ll stop working to make the Church break its silence and denounce pedophiles. In his case, he was lied to: the promise of keeping Allaz away from children meant instead moving him to France, where he continued to abuse children.

Pittet believes that in his country, things have improved regarding the Church’s actions on clerical sexual abuse. However, for what he knows, that’s not the case in France and Italy.

“Because of this, the pope’s words are important. There are pedophiles in parishes but also in the hierarchy who pretend nothing is happening, who move pedophile priests to another parish as if this solved the problem.”

“They keep the secret, and new children become victims,” Pittet said.

The pope decided to write the preface after reading the draft for the book, sent to him by Pittet at his Vatican residence, the Domus Santa Marta.

Pope Francis has commented on the clerical abuse problem on many previous occasions. For instance, in remarks he delivered last November but which were released last week, he said that when priests or religious are involved in the sexual abuse of minors, “it’s clear that the presence of the devil is in action, ruining the work of Jesus through those who were supposed to communicate Jesus.”

Despite the pope’s strong words, some critics have questioned his actions. For instance, they often cite that despite the announcement of a new Vatican tribunal to hold bishops accountable for cover-ups, no actual steps have yet been taken to get it up and running.

Then there have been several instances in which the Church has continued to be slow in addressing the issues, such as the case of the founder of the Peruvian lay movement known as the Sodalit, the founder of which has long been accused of sexual abuse.

Others, however, have applauded Francis’s recent decision to appoint Boston’s Cardinal Sean O’Malley, a member of the council of cardinals that advises the pope and head of the Pontifical Commission for the Protection of Minors, to the Congregation for the Doctrine of the faith, the powerful Vatican department which, since 2001, has played lead in prosecuting cases under Church law for priests charged with sexual abuse.