By Alessandro Speciale

Religion News Service

(RNS) "Radical secularism" is gaining ground in American society and poses a "grave threat" to the Catholic Church's freedom of expression in the public square, Pope Benedict XVI told a group of U.S. bishops on Thursday (Jan. 19).

The delegation of bishops from the mid-Atlantic region, led by Washington Cardinal Donald Wuerl, is in Rome for a series of regular "ad limina" visit that occur once every five years.

Benedict said bishops must help Catholic politicians understand that it is "their personal responsibility to offer public witness to their faith," especially regarding the respect for human life.

Catholics must be on guard to confront a "reductive secularism," Benedict said, which tries to "delegitimize the church's participation in public debate."

The pontiff warned that America's "cherished" tradition of "religious freedom" is under threat as the nation's moral consensus has been "eroded" by "powerful new cultural currents" that not only run counter to "Judeo-Christian tradition, but (are) increasingly hostile to Christianity as such."

Benedict's message echoed a recent campaign by the U.S. Conference of Catholic Bishops, which has warned of a "national conflict between church and state of enormous proportions" over same-sex marriage, contraception mandates and other issues.

Benedict warned that the separation of church and state must not be invoked to force the church to "be silent on certain issues," or to sideline believers in "determining the values which will shape the future of the nation".

New York Archbishop Timothy Dolan, president of the bishops' conference, was not in Rome but thanked the pope in a statement for speaking "eloquently and powerfully on the threats to the church's moral witness in public life."