The Roman Catholic Church in Maryland is gearing up for a battle in the state legislature over same-sex marriage.Democratic Gov. Martin O\'Malley has said passing a bill legalizing marriage for gay couples is one of his top priorities in the legislative session beginning in January, The Baltimore Sun reported. Catholic bishops, in a statement sent to parishes, said that would be a violation of the U.S. Constitution\'s guarantee of religious freedom.The 16-page statement, \"The Most Sacred of All Property: Religious Freedom and the People of Maryland,\" was signed by Cardinal Donald Wuerl of Washington, Bishop W. Francis Moody of Wilmington, Del., and former Baltimore Archbishop Edwin F. O\'Brien, who has been transferred to Rome.The bishops said if the legislation passes Catholic business-owners might risk discrimination claims if they do not provide services for gay weddings or provide health coverage for gay spouses.The state Senate approved a same-sex marriage bill in 2011. Supporters withdrew the bill from a House vote because they did not have enough votes for passage, but say it has a better chance with O\'Malley\'s support.