Pope Francis has urged priests who have raped and molested children to turn themselves in and prepare for “divine justice,” in his strongest condemnations yet of the Roman Catholic Church’s sexual abuse crisis.

The pope pledged Friday that the church would “never again” cover up or dismiss sexual abuse cases.

“To those who abuse minors I would say this: convert and hand yourself over to human justice, and prepare for divine justice,” Francis said during his annual Christmas address to the Curia, the Vatican’s central administration, Reuters reported.

The pope admitted that the church had failed to act on this issue in the past, acknowledging that leaders refused to believe victims.

“It is undeniable that some in the past, out of irresponsibility, disbelief, lack of training, inexperience, or spiritual and human short-sightedness, treated many cases without the seriousness and promptness that was due,” he said.

“That must never happen again. This is the choice and the decision of the whole church.”

Mondadori Portfolio via Getty Images Pope Francis and the Roman Curia during the Christmas greetings at Clementine Hall in Vatican City on Friday. The pope addressed the Roman Catholic Church's sexual abuse crisis in his remarks.

The pope’s message comes at the end of one of the toughest years of his papacy. Francis started off the year by passionately defending a Chilean bishop accused of covering up abuse of minors, dismissing the testimony of abuse survivors as “slander.” Months later, he admitted he made “grave errors” in his handling of Chile’s abuse crisis.

Later in the year, the crisis in the U.S. reached a fever pitch after a Pennsylvania grand jury published a devastating report into sexual abuse in the state that identified 301 predator priests and more than 1,000 victims. The report has sparked similar attempts by state prosecutors around the country.

Just this week, Illinois Attorney General Lisa Madigan released a damning report accusing the Catholic Church in Illinois of withholding the names of at least 500 priests accused of abuse.

Madigan’s preliminary report concludes that her state’s Catholic dioceses are incapable of investigating themselves and “will not resolve the clergy sexual abuse crisis on their own.”

The pope has also been beset this year by accusations from a Vatican insider that Francis and others in the hierarchy were complicit in covering up abuse carried out by former American Cardinal Theodore McCarrick. Francis has not directly responded to the claims he was complicit, which are still unsubstantiated.

ASSOCIATED PRESS Francis said February's bishops' summit on sexual abuse will address protecting children, bringing healing to victims and improving training in seminaries.

In response to the crisis, the pope has called for a bishops’ summit on sexual abuse in February, which will be attended by the heads of about 110 national Catholic bishops’ conferences, the leaders of religious orders and abuse experts, Reuters reports.

On Friday, Francis said the summit will address how to protect children, bring healing to the victims, and improve training on the issue in seminaries. He vowed to turn “past mistakes” on handling the crisis into “opportunities for eliminating this scourge” in the church and in broader society.

Francis also thanked journalists for highlighting the voices of Catholic victims. At the same time, he emphasized that the Catholic Church isn’t the only institution dealing with sexual abuse cases.

“If this grave tragedy has involved some consecrated ministers, we can ask how deeply rooted it may be in our societies and in our families,” Francis said. “Consequently, the church will not be limited to healing her own wounds, but will seek to deal squarely with this evil that causes the slow death of so many persons, on the moral, psychological and human levels.”

ASSOCIATED PRESS Francis emphasized in his remarks to the Roman Curia on Friday that the Catholic Church isn't the only institution dealing with sexual abuse cases.

Given the church’s dismal track record on policing itself in the past, abuse survivors and their advocates were skeptical about Francis’ new comments on the crisis.

Anne Barrett Doyle, co-director of the abuse tracking website Bishop-Accountability.org, told HuffPost she thinks the pope is “indulging in make-believe and misdirection.”

“In commanding child molesters to turn themselves in, Francis is pretending. He’s pretending that sick men suddenly can see the light,” she said. “He’s pretending the problem lies with perpetrator priests and some ignorant bishops of the past rather than with an ongoing cover-up approved by the Vatican itself.”

She criticized Francis for bringing up the Catholic Church’s “thread-worn” self-defense that children are abused in all sectors of society. Barrett Doyle said the church doesn’t need a spiritual reboot but a fundamental reform of its laws. Francis’ Christmas message to the Curia hasn’t assured her that he sees the problem clearly.

“Let’s hope he is working on a host of concrete systemic reforms that he plans to roll out in February,” she said.

Leaders of the Survivors Network of those Abused by Priests (SNAP), a national advocacy organization, told HuffPost that the Christmas message amounted to “flowery words backed up by inaction.”

SNAP said it’s hoping the February summit will result in greater transparency in future sexual abuse cases and the resignations of all prelates who have minimized or concealed sex crimes in the past. The group also wants bishops to stop spending money on lobbying efforts to prevent statutes of limitation reform and to turn over all documents related to abuse to law enforcement officials.

“Yes, Pope Francis’ words were powerful,” SNAP said in a statement. “But unless those words are backed up by action, they mean nothing.”

This article has been updated with comments from SNAP and BishopAccountability.org.