The Archdiocese of Philadelphia will host a seven-hour vigil Friday evening at the Cathedral Basilica of SS. Peter and Paul, rallying the faithful to pray that the church atones for the sin of sexual abuse committed by its clergy, and that the victims will be healed.

The observance, called "Have Mercy on Us Lord, O Lord: A Prayer Vigil of Reparation and Petition," asks the region's 1.5 million Catholics to beseech God for mercy at a time when the church is grappling with a crisis that is shaking its foundation.

"We come to make reparation for our own sins, and those of our bishops and priests," states a flyer posted on the archdiocese's website.

Last month, a Pennsylvania grand jury issued a report that Catholic leaders in six dioceses — Pittsburgh, Harrisburg, Allentown, Scranton, Erie, and Greensburg —  had covered up decades of child sex abuse involving more than 1,000 victims and hundreds of priests.  Philadelphia and Altoona-Johnstown had already been the subjects of previous grand juries that had investigated their handling of clergy sex-abuse claims.

The vigil, which begins at 5 p.m., will include a prayer service in English and Spanish from 7 to 8 p.m. The  remaining hours until midnight are reserved for silent personal prayer. The observance falls on the Feast of Exaltation of the Holy Cross, which celebrates events including the recovery of the cross on which Christians believe Jesus Christ was crucified, found by St. Helena in 326.

Among those offering prayers will be a group of parishioners from Our Lady of Mount Carmel Church in Doylestown, who are scheduled to travel to the vigil on a bus from Bucks County.

Abuse survivor Juan Carlos Cruz, of Philadelphia, who shared his story with Pope Francis during a visit to the Vatican in April, said that praying is a good idea, but said that alone won't help survivors.

"Turn in the perpetrators and those who covered for them. That is a good way to make amends as well," Cruz said in an Inquirer and Daily News interview.

In a statement, archdiocesan spokesperson Kenneth A. Gavin said that the prayer vigil is just one part of a multifaceted response to what he called "the past institutional failures of the Church to protect children and young people entrusted in her care."

The archdiocese has dedicated more than $14 million to its Victim Assistance Program, which has provided aid to survivors and their families including counseling, medication, and vocational aid, Gavin said. New policies also have been enacted to reform the way the archdiocese protects children and families and investigates allegations of sexual misconduct, he added.

Since the release of the Pennsylvania report, at least 10 other states, including New Jersey, have launched investigations into alleged clergy sexual abuse and cover-ups. And on Wednesday, German media outlets reported that an investigation by the German bishops conference has revealed decades of abuse by clergy that involved 3,677 victims over nearly 70 years.

Last month, Pope Francis was accused by Archbishop Carlo Maria Vigano of covering up the sexual misconduct of ex-Cardinal Theodore McCarrick, former archbishop of Washington, who was removed by the pontiff after an accusation that McCarrick had groped a teenage altar boy in the 1970s was deemed credible. Additional allegations of sexual abuse of minors and seminarians against McCarrick emerged, revealing that his alleged misconduct was widely known for decades.

The Council of Cardinal Advisers has expressed "full solidarity" with Pope Francis, and the Vatican is preparing a detailed response to the accusations made by Vigano, former papal ambassador to the United States. On Thursday, the pope met with U.S. cardinals and bishops at the Vatican to discuss the sexual-abuse scandal. The pontiff has scheduled a four-day meeting for February 2019 when presidents of more than 100 bishop conferences will gather at the Vatican to explore the prevention of sexual abuse in the church.