Pope Benedict addressed five of the 15 regional groups of U.S. bishops making their periodic "ad limina" visits to the Vatican, which began in late November and ended May 19. The speeches touched on themes applicable to dioceses across the country.

One constant was the Pope's warning against the demoralizing effects of secular culture, which he said had led to a "quiet attrition" among the church's members, who must therefore be the first targets of "re-evangelization."

Yet the Pope argued that moral decay is also threatening the stability of secular society itself. He noted what he called an "increased sense of concern on the part of many men and women, whatever their religious or political views" that a "troubling breakdown in the intellectual, cultural and moral foundations of social life" has imperiled the "future of our democratic societies."

Therefore, he said, "despite attempts to still the church's voice in the public square," Catholics should insist on providing "wisdom, insight and sound guidance" to "people of good will." Using the non-religious "language" of natural law, he explained, the church should promote social justice by "proposing rational arguments in the public square."

This duty is incumbent not only on bishops, the Pope said, but also on Catholic politicians, who have a "personal responsibility to offer public witness to their faith, especially with regard to the great moral issues of our time." He identified the issues as "respect for God's gift of life, the protection of human dignity and the promotion of authentic human rights."

In particular, Pope Benedict called Catholics to the front lines in defense of "that most cherished of American freedoms, the freedom of religion," which he said was especially threatened by "concerted efforts" against the "right of conscientious objection ... to cooperation in intrinsically evil practices."

The Pope's presumed reference there was to an Obama administration plan, vociferously protested by U.S. bishops, which would require that the private health insurance plans of most Catholic institutions cover surgical sterilization procedures and birth control.

American society also is served by the church's promotion of sexual morality, Pope Benedict said, since a "weakened appreciation of the indissolubility of the marriage covenant, and the widespread rejection of a responsible, mature sexual ethic grounded in the practice of chastity, have led to grave societal problems bearing an immense human and economic cost."

The Pope characterized the bishops' defense of traditional marriage against proponents of same-sex unions as a matter of "justice, since it entails safeguarding the good of the entire human community and the rights of parents and children alike."

Even in connection with the church's most terrible scandal in living memory -- the widespread sexual abuse of minors by priests -- Pope Benedict noted benefits that the church can offer the non-Catholic world.

"It is my hope that the church's conscientious efforts to confront this reality will help the broader community to recognize the causes, true extent and devastating consequences of sexual abuse, and to respond effectively to this scourge which affects every level of society," he said.

Although designed to serve Catholics, the church's educational institutions also enrich society at large, the Pope said.

Catholic schools' "significant contribution ... to American society as a whole ought to be better appreciated and more generously supported," he said. And Catholic universities, following in a tradition that professes the "essential unity of all knowledge," can be a bulwark against a current trend toward academic overspecialization.

Unity among Catholics can also promote harmony across American society, the Pope said.

Noting the "difficult and complex" legal, political, social and economic issues surrounding immigration in the U.S. today, the Pope suggested that a closer "communion of cultures" among the ethnic groups that make up the church in America could reduce ethnic tensions outside the church.

"The immense promise and the vibrant energies of a new generation of Catholics are waiting to be tapped," the Pope said, "for the renewal of the church's life and the rebuilding of the fabric of American society."