Vatican City • Pope Francis urged Catholic bishops to dream of a future free of the mistakes of the past as he opened a global church leadership meeting Wednesday amid renewed outrage over the priestly sex abuse and cover-up scandal.

Yet down the block from the Vatican’s synod hall, about two dozen abuse survivors staged a sit-in, demanding their cause be taken up at the meeting and voicing outrage that some of the delegates had covered up for abusive priests.

“Make ‘Zero Tolerance’ Real,” read one protest sign.

Francis welcomed more than 250 priests, bishops and cardinals — as well as 34 young Catholics — to a monthlong meeting on ministering to future generations, urging young and old to listen to one another without prejudice.

He prayed for God’s help to ensure the church “does not allow itself, from one generation to the next, to be extinguished or crushed by the prophets of doom and misfortune, by our own shortcomings, mistakes and sins.”

The Oct. 3-28 synod comes amid new revelations about decades of sexual misconduct by priests and cover-ups in the U.S., Chile, Germany and elsewhere. That has sent confidence in Francis’ leadership to all-time lows among the American faithful.

A new survey by the Pew Research Center found that just 31 percent of U.S. Catholics felt the pope was doing an excellent or good job in addressing the abuse issue, down from 45 percent in January and 55 percent in 2015.

It has been a disastrous year for the pope on the abuse front, after he botched a prominent cover-up scandal in Chile before changing course. More recently, he has been accused of rehabilitating an American ex-cardinal who pressured seminarians to sleep with him.

Those cases, coupled with the release of devastating studies about decades of abuses and cover-ups in Pennsylvania and Germany that predated his papacy, have fueled doubts about his oft-stated pledge of having “zero tolerance” for that, since implicated bishops remain in place.

“Pope Francis talks about ‘zero tolerance,’ and that bishops who cover-up should be removed and put on trial,” said Alessandro Battaglia, who was 15 when he was abused by a Milan-area priest who last month was convicted and sentenced to over six years in prison.

The current archbishop of Milan, Mario Delpini, testified at the trial of the Rev. Mauro Galli that he had transferred Galli to another parish rather than report him to police or keep him away from other potential victims, as Battaglia’s family had requested.

Despite publicity about the case, Francis named Delpini archbishop of Milan in July and named him a papal delegate at the synod.

“What is this ‘zero tolerance’?” Battaglia asked at the protest Wednesday. “If he wants to give a sign of zero tolerance and coherence and credibility, remove him [Delpini].”

Among those participating in the protest were the hearing impaired victims of the notorious Antonio Provolo Institute in Verona, Italy, where deaf children were sodomized for years by Catholic priests and brothers. The victims have found no justice even though Francis and the Vatican were informed of their plight in 2014. They are now preparing a case to take to Italian prosecutors.

“Young people should question the way the church has dealt with this in the past,” said Matthias Katsch of the Ending Clergy Abuse global advocacy group.

Francis didn’t refer directly to the abuse scandal in his homily at Mass or later Wednesday in his opening speech to the synod. He did, however, call for an end to the “scourge of clericalism” — the culture that puts clergy on a pedestal and unaccountable to their flocks, which Francis has blamed for the scandal.

“Clericalism is a perversion and is the root of many evils in the church,” he told the delegates. “We must humbly ask forgiveness for this and above all create the conditions so that it is not repeated.”