Obama and Biden to Attend National Prayer Service President Obama and Vice President Joseph R. Biden Jr. will go to the Washington National Cathedral on Jan. 22, the day after their second inaugural ceremony, to participate in the National Prayer Service, held every four years to commemorate the inauguration of the president. Mr. Obama's inaugural committee will issue a formal announcement about the event later Tuesday morning, and the official said details about the other participants would become available in the coming weeks. The issue of religion has often bedeviled Mr. Obama during his presidency; during his 2008 presidential campaign, his longtime relationship with the Rev. Jeremiah Wright, a black pastor prone to provocative comments, stirred controversy. And Mr. Obama offended gay rights activists at his second inaugural by inviting the Rev. Rick Warren, an outspoken opponent of abortion and same-sex marriage, to deliver the invocation. The National Prayer Service, a tradition that dates back to the presidency of George Washington, will include prayers, readings, blessing and hymns delivered by religious leaders from across the United States, the official said, adding that it will represent "America's diversity of faith and belief." Mr. Obama, Mr. Biden and their wives also attended the Cathedral prayer service in 2009, but Cathedral officials say not all prayer services have been held there. Former President Bill Clinton, for instance, chose Metropolitan AME Church, a historic black church in downtown Washington, for both of his inaugural prayer services (perhaps contributing to the oft-quoted maxim in Washington that Mr. Clinton was "the nation's first black president.") The soaring Cathedral, with its gargoyles and Gothic Revival architecture is, technically, an Episcopal church. But its dean, the Very Rev. Gary Hall, said the cathedral was founded in 1907 "with the idea of being a spiritual home for the nation, a kind of Westminster Abbey for America." He said part of the Cathedral's mission is "to be a gathering place for the nation in both times of celebration and times of tragedy." The Cathedral also announced Tuesday plans for a special exhibit, "Presidents at the Cathedral," which chronicles past visits by United States presidents during the course of the Cathedral's 105-year history. The exhibit will be open in January; a special forum, free and open to the public, about the history of the presidential inaugural is also scheduled to be held at the Cathedral on Sunday January 20, the day before the president's public swearing in. But admittance to the National Prayer Service will be by invitation only, officials said.