A Vatican representative told U.S. bishops Thursday "we know we are going through difficult times" as the Roman Catholic leaders met in the wake of two new assaults to their credibility.

The pope's nuncio to the United States, Archbishop Gabriel Montalvo, did not refer directly to the ongoing clerical sex abuse crisis (search), or to the American church's latest problems -- a bishop resigning after being charged with a felony and a leading layman attacking some members of the hierarchy.

But Montalvo acknowledged the church's difficulties, adding the troubles have been "magnified to destroy the moral credibility of the church." He said any adversity can be overcome by prayer and faith in God.

Montalvo spoke at the beginning of a three-day meeting of bishops that will keep most discussion of the abuse crisis behind closed doors. Still, the issue is unavoidable.

Outside the meeting, Voice of the Faithful (search), a group that wants a greater role in church affairs for the laity, called on bishops in every diocese to release all personnel records related to credible abuse accusations.

"We are furious that these revelations of abuse have taken so many years to be disclosed and dealt with by our bishop," said Sandy Simonson, a Voice member from Phoenix.

She was referring to Phoenix Bishop Thomas O'Brien, who resigned Wednesday in the wake of his arrest on a charge of leaving the scene of a fatal hit-and-run accident.

O'Brien also struck a deal with a prosecutor announced June 2 in which -- to avoid indictment -- he acknowledged sheltering priests accused of molestation.

The very hour of O'Brien's arrest Monday, former Oklahoma Gov. Frank Keating, leader of the National Review Board the bishops created to monitor their sex abuse reforms, stepped down under pressure. That looked bad enough, but his resignation letter compounded matters by questioning a few bishops' commitment to cleaning up.

"To resist grand jury subpoenas, to suppress the names of offending clerics, to deny, to obfuscate, to explain away; that is the model of a criminal organization, not my church," wrote Keating, though he added that "most bishops" fully support the review board.

In a New York Times opinion piece Thursday, Keating expressed optimism that the church will ultimately pull through the crisis. But he reiterated that a few leaders "chose to resist and obstruct" his board.

The bishops "wanted to come to St. Louis showing they have regained their bearings" but these developments demonstrate the opposite, said journalist David Gibson, whose book The Coming Catholic Church will be published in July.

"Every time they try to get back on track, they find themselves diverted," said Gibson, a Catholic convert. "They are their own worst enemy." Yet under the church's government system "the bishops have to lead us out of this crisis, if it's going to happen."

As the bishops confer, more critics are hovering nearby.

The Survivors Network of those Abused by Priests gave the bishops a "D" grade for efforts the past year, and called for Keating's successor to be another person with experience as a prosecutor. SNAP holds its first national assembly in St. Louis from Friday through Sunday.

Monsignor Francis Maniscalco, spokesman for the bishops' conference, disputed SNAP's assessment. He said the bishops willingness to let independent observers judge their deeds proves the church's leaders are sincere.

Another advocacy group, Survivors First, announced an updated Internet listing that names 1,608 priests accused of molesting. The group says eight of them remain in ministry. It also launched www.bishop-accountability.org -- a Web site collecting documents about abuse.

Keating said he planned to step down anyway. But he resigned after likening some secretive bishops to the Mafia in a Los Angeles Times interview. In response, Los Angeles Cardinal Roger Mahony said bishops should consider forcing Keating out.

The spat stemmed from disagreements over a questionnaire all bishops are supposed to file on the extent and patterns of sex abuse cases in their dioceses.

The bishops will discuss that survey and other problems implementing reforms in a closed-door session Thursday afternoon with three review board members and the people hired to conduct the survey from John Jay College of Criminal Justice.

"When the hierarchy can't even comply with a survey that it itself commissioned, you know you have deep differences," Gibson said.

The review board says 135 of the nation's 195 dioceses have already sent reports, meaning a third have yet to file.

As for O'Brien, the United States Conference of Catholic Bishops (search) has no official role in individual members' problems.

But O'Brien's troubles could be especially unnerving for bishops because they follow other recent embarrassments among colleagues, such as the resignation of Cardinal Bernard Law as Boston archbishop since the hierarchy last gathered. While no longer leader of Boston's Catholics, Law was among the bishops for the opening prayers on Thursday.