Pastor to Power

August 6, 2007— -- He has preached the gospel to 215 million people in 185 countries. He's provided spiritual guidance to tens of millions of people, and is one of the most revered religious figures of modern times.

The Rev. Billy Graham, the world's most famous evangelist, has also for the past 60 years ministered privately to some of the world's most powerful men: the presidents of the United States.

All four living presidents, George W. Bush, Bill Clinton, George H.W. Bush, and Jimmy Carter, and four first ladies, Laura Bush, Senator Hillary Clinton, Barbara Bush and Nancy Reagan, sat down to talk to Charlie Gibson and ABC News about Graham, his influence on their lives, and the role of faith in the presidency.

Watch the full interview with Graham and the Presidents on a special edition of "20/20" Friday, August 10 at 10 p.m. EDT

Graham told Gibson he thinks of these men as friends: "Each one I've known long before they ever became president, been in their homes many times; always called them by their first names, until they became president." And they are just four of the eleven presidents that he has known.

Graham has been, to varying degrees, a guest in the White Houses of Harry Truman, Dwight Eisenhower, John F. Kennedy, Lyndon Johnson, Richard Nixon and Gerald Ford as well. In an extraordinary occurrence, Graham spent both the last night of the Johnson administration and the first night of the Nixon administration in the White House.

But in a country founded on the separation of church and state, what role does faith play in its most powerful office? "I don't think the president is any different than anybody else when it comes to wonder," the senior George Bush said.

"I prayed more and needed more [spiritual] counseling when I was president than any other four years of my life," said Jimmy Carter.

For many of the past 11 presidents, Graham has provided that counseling for them and their families.

When faced with the Monica Lewinsky scandal, Hillary Clinton told Gibson that Graham gave her the confidence "that what I was doing, no matter what the rest of the world thought, was right. Right for me, right for my family and right for my country. And I will never forget that."