U.S. President Barack Obama's first full day in office was a mix of policy and prayer. He met with top military and economic advisors, and attended a nondenominational service at Washington's National Cathedral.  

After the swearing-in ceremony, the parade, and the inaugural balls, it was time for the new president to get to work.

"What a moment we are in," he said. "What an opportunity we have to change this country!"

Mr. Obama met Wednesday with members of his staff and Cabinet, and formally approved tough new rules on ethics and government transparency, and froze the salaries of his top aides.

"Public service is a privilege. It is not about advantaging yourself. It is not about advancing your friends or your corporate clients," he said. " It is not about advancing an ideological agenda or the special interests of any organization. Public service is simply and absolutely about advancing the interests of Americans."

In the hours that followed, the president focused on the biggest issues facing the American people - the economy, and the wars in Afghanistan and Iraq.

Mr. Obama met behind closed doors with his economic team - a meeting that likely focused on his efforts to win Congressional approval of a massive plan aimed at stimulating the economy.

Then he conferred in private for the first time as president with the men who are leading the war effort - a chance to review strategy and troop deployments.

He also engaged in some personal diplomacy, making clear early on that his administration is interested in preventing further violence and promoting peace in the Middle East.

White House Press Secretary Robert Gibbs says Mr. Obama called Egyptian President Hosni Mubarak, Jordan's King Abdullah, Israeli Prime Minister Ehud Olmert and Palestinian President Mahmoud Abbas.

Gibbs says the president stressed his commitment to the peace process and vowed to work to strengthen the cease-fire in Gaza.

But before he tackled matters of commerce and state, President Obama took time to seek divine guidance.

His first public appearance of the day was at the last official inaugural event - a prayer service at the National Cathedral.

The president sat in the front pew as Reverend Andy Stanley led the congregation in a prayer.

"Grant to Barack Obama, President of the United States, and to all in authority, your grace and goodwill," he said. "Bless them with your heavenly gifts, give them wisdom and strength to know and to do your will."

Christian, Jewish, Muslim and Hindu clergy took part in the service - an inaugural tradition dating back to George Washington.