The Reverend Billy Graham, 80 years old and suffering from Parkinson's disease, grasped the lectern before an electrified congregation in Memorial Church yesterday morning, delivering an evangelical oration tailored for the undergraduate population.

Graham, the seminal figure in American Christianity this century, was greeted by a standing room only crowd of more than 1,500--including students who had spent the night on the church's front steps to get a seat. He has visited Harvard twice before but never given a Sunday sermon here.

The celebrated preacher--who compared his visit to Harvard to that of a mule at the Kentucky Derby--spoke on "The Real Meaning of the Cross," exhorting his listeners to turn to God, confess and repent their sins and embrace the cross.

"Young people today, especially students, are searching for something they don't know what," Graham said.

Addressing the undergraduates assembled, Graham declared that even sexual intercourse is more pleasurable with "the love of Christ when you come to your marriage bed."

"You'll see a height of ecstasy," Graham said. "My wife is a believer and so am I, and we've had many such times."

Plummer Professor of Christian Morals and Minister in the Memorial Church Peter J. Gomes beamed at the enthusiasm students showed for Graham, joking that 20 years ago, the sight of undergraduates sleeping on the front steps of Memorial Church would have sent him running for cover, fearing a student protest.

"Those of you who can see and can hear, be grateful!" Gomes told the congregation.

For Graham, who was forced to cancel a visit to Harvard last spring because of illness, yesterday's trip to Harvard may be one of his last.

"My time is drawing to a conclusion on this earth," Graham said, adding that his faith has given him confidence to face life after death.

This afternoon, Graham will speak again to the University, delivering a speech to the Institute of Politics at the Kennedy School of Government entitled "Is God Relevant for the 21st Century?"

In his sermon, Graham condemned those who strip Christianity of its meaning, saying that some Christians wear crosses around their necks as "costume jewelry."

He argued that the cross symbolizes the most important principles of Christianity--particularly the burden borne by Jesus.

"His real sorrow was when God placed on him the sins and evils of all of us," Graham said. "He became guilty of all that you and I have done wrong...all of the racial prejudices, all of the lies."

At the service, University Marshal Richard M. Hunt delivered an official greeting, calling Graham "chaplain to this nation."

Between performances of two major American choral works, former Undergraduate Council presidential candidate T. Christopher King '01 read the morning's New Testament reading. The bulging crowd included former Illinois Governor James R. Edgar who sat next to Lowell House co-Masters Diana L. Eck and Dorothy A. Austin.

Graham, who counseled every president since Harry Truman, began his career more than a half century ago and has visited more than 100 countries--including the nations of the former Soviet bloc--with his evangelical message.

In his remarkable career, Graham managed to avoid the financial and sexual scandals that have plagued other evangelists. He never built a church of his own, instead directing his followers to their own local churches.