The campaign initially was meant to highlight the divine in everyday aspects of marriage. It has turned recently to more political concerns, such as the creation of a committee to lobby against same-sex marriage bills such as the one pending in the District.

The pastoral letter, which passed 180 to 45, spells out the traditional position of the Roman Catholic Church. Some Catholic critics have called it "unpastoral" for its focus on threats to marriage, including, in the bishops' view, contraception and cohabitation, which the document compares to original sin.

The D.C. measure was not addressed directly in the pastoral letter, although it was a topic of discussion in the halls at the annual bishops' meeting at the Baltimore Marriott Waterfront Hotel.

In addition to the council action, the D.C. Board of Elections and Ethics ruled a proposed ballot initiative defining marriage as between a man and a woman cannot go forward, reaffirming an earlier ruling that such a vote would be discriminatory.

The Archdiocese of Washington said last week Catholic Charities, its social service arm, would be unable to continue its partnerships with the city if the current bill isn't changed.

Washington Archbishop Donald W. Wuerl, in an op-ed piece that appeared on The Washington Post Web site Tuesday, said church officials recognize the council "is firmly committed to opening marriage to homosexual couples. We are asking new language be developed that more fairly balances different interests -- those of the city to redefine marriage and those of faith groups so they can continue to provide services without compromising their deeply held religious teachings and beliefs."

Church-state experts disagree on the measure's legal impact and how it compares with same-sex marriage measures in other states. The archdiocese and some lawyers said measures elsewhere offer faith groups more exemptions from, for example, handling adoptions for same-sex couples or offering health benefits to same-sex partners of employees. Council members and others said the new law doesn't put any additional burden on the church that isn't already required by the city's civil rights law.

Connecticut's measure explicitly exempts privately funded adoption services from being required to work with same-sex couples.

The dispute is complex, because such issues are governed simultaneously by local and federal civil rights laws that ban discrimination based on sexual orientation or religion and federal employment laws. Experts said some disagreements related to the D.C. measure have never been litigated, said Robert Tuttle, a church-state expert at George Washington University.

"D.C.'s bill looks to be narrower than some passed in New England," Tuttle said.

Cynthia DeSimone, deputy general counsel of the archdiocese, said the city's civil rights law does not require the church to place children for adoption with same-sex couples. Council member David A. Catania (I-At Large) has said the city law does make that requirement.

"It is difficult to compare other states' measures, because each interact differently with other laws in their respective states," said DeSimone, who noted the laws in New Hampshire, Vermont and Connecticut are all less than a year old. "That being said . . . they do provide broader exemptions."

The D.C. measure had exempted religious groups from having to provide marriage-related services and facilities to same-sex couples unless those groups offer such things to the general public.

At the request of the archdiocese, the council removed the clause about the general public, but it added a list of services that "promote" marriage that would be exempt from the law's requirements.

This would make it difficult for the church to argue services not specified in the law should also be exempt, said Art Spitzer of the local ACLU office.

Many issues haven't played out in court, Spitzer said, including the reach of the 1993 federal Religious Freedom Restoration Act. The church could argue under that act, extending health-care benefits, for example, would be a burden to its religious beliefs. "I think they could make that case," he said. "I think they might lose, but it's not been litigated."