Pope Benedict XVI celebrated his first public Mass in the U.S. Thursday, reading a homily in which he addressed a host of problems facing the church today, including sex abuse within the U.S. Catholic Church.

Click here for full text of the pope's prepared homily.

The pope addressed the tens of thousands gathered at Washington Nationals stadium, characterizing America as a "country of hope" and calling on the virtue of forgiveness to help heal the pain caused by the sex abuse scandals involving American clergy.

"No words of mine could describe the pain and harm inflicted by such abuse," the German-born pope told the crowd.

This is the third time Pope Benedict XVI has addressed the issue during his U.S. trip.

Vatican observer Father Jonathan Morris, who was there for the homily, told FOX News this is exactly what many within the church have been waiting — and wanting — to hear.

He paraphrased the pope's message: "The whole character of our civilization right now is under attack," Morris told FNC. "We have to accept the sins of the church. We have to recognize as well that this comes forth from a society that is very sick."

Pope Benedict XVI also praised America as a land of opportunity, though he said the nation's promise fell short for Indians and blacks.

"Your ancestors came to this country with the experience of finding new freedom and opportunity," Benedict said.

"To be sure, this promise was not experienced by all the inhabitants of this land; one thinks of the injustices endured by the native American peoples and by those brought here forcibly from Africa as slaves."

Click to read blogs from Father Jonathan, Laura Ingle, Lauren Green and Greg Burke.

A crowd of 46,000 was expected for the pope's Mass, but the demand for tickets doubled the supply, organizers said.

The pope, wearing scarlet vestments, led the service from an altar erected in centerfield of the recently inaugurated baseball stadium.

Barbara and Michael Loh of Williamsburg, Va., sat alone in the stands taking in the scene. They were among the first to arrive.

"I've been Catholic all my life and ... my dream has always been to see the pope," said Barbara Loh, tearing up.

At 5:45 a.m., more than four hours before the Mass, it was standing-room only on subways. Vendors hawked Vatican flags and souvenir buttons, but there were few takers as people hurried toward the stadium.

For others, there was nothing more important than getting in, and many people without tickets stood outside the subway station with signs pleading for extras.

Patty Trail, 54, pastoral associate at a church in Virginia Beach, Va., drove overnight to bring two priests to the Mass. She didn't have a ticket but said she was happy to at least be in the vicinity of the pope.

"Just to be out here, just to be in the presence," she said. "D.C. feels different."

Benedict spent the first full day of his U.S. journey Wednesday sharing a platform with President Bush and laying out his analysis of the American church to the nation's bishops.

Before Benedict's arrival, polls showed most Americans knew little or nothing about him. Those who have watched him so far have found a German-born pontiff who speaks excellent English, appears vigorous for his 81 years, mostly prefers script to spontaneity and displays a keen sense of the critical issues facing his 65-million member American flock.

One of larger questions hanging over Benedict's first U.S. trip as pontiff was whether and how he would address the clergy sex abuse scandal, which has claimed thousands of victims, cost the church more than $2 billion in court costs and settlements and led six dioceses to declare bankruptcy.

The answer: He talked about it early, often and with conviction, although not to the satisfaction of many victims and their advocates.

In an address to U.S. bishops Wednesday night at the Basilica of the National Shrine of the Immaculate Conception, Benedict called the scandal a "deep shame." He decried the "enormous pain" that communities have suffered from such "gravely immoral behavior."

He also said the problem needs to be viewed in the wider context of secularism and the over-sexualization of America, and called for "a determined, collective response."

Bishop Gregory Aymond of Austin, Texas, chairman of the bishops' Committee for the Protection of Children and Young People, said Benedict made it clear that more work remains and that the impact of the scandal damages not just the Catholic church but faith in God.

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"Some would say the crisis is over," Aymond said. "As long as victims are still hurting and broken and there is a need for reconciliation, it is still critical. At the same time, we want to recognize that we as a church have moved forward ... The Holy Father gets it."

Aymond also welcomed Benedict's endorsement of Chicago Cardinal Francis George's comment that the crisis had been "very badly handled."

"I believe we have to tell it like it is, and I was glad that he said that," Aymond said. "All of us as bishops, as leaders, have to examine our consciences."

Advocates for victims have complained that no bishops have been disciplined for failing to warn parents and police about abusers.

Although the comments on sexual abuse were much anticipated, Benedict's address went well beyond them. He talked about Catholics' responsibility to raise their voices in the public square, the need to encourage more men to enter the priesthood, the influx of Hispanic immigrants who have transformed the church, and the importance of strengthening families.

"None of what he's said has surprised me, because he's said so much before," said Denver Archbishop Charles Chaput. "But he's spoken in such a succinct way and covered all the bases."

"Even though he's a theologian and John Paul II was a poet-philosopher, all of us think in terms of speaking, Benedict is so much clearer," Chaput said. "Not only in his use of English, but in the way he formulates things."

The pope's presence has deeply touched the devout. One young woman, awaiting his arrival at the basilica where he addressed the bishops, began weeping at first sight of the pope's motorcade, which was projected on a large screen. He was 10 minutes away.

Elsa Thompson of Washington, D.C., who as a basilica tour guide knows the stories behind nearly every mosaic and stained-glass window, said that when she looks at Benedict, she sees a moral authority and a clear voice in a confused world.

Yet she too wonders how the scholarly pontiff's message will translate Thursday in a baseball stadium, as Catholics from around the country are introduced to him in person.

"I watched him on TV at the White House, and I thought, 'How many people actually grasp what he's saying?' — including me," Thompson said. "Yet at the same time, I felt challenged, because he is a teacher."

After his appearance at the stadium Thursday, Benedict will address Catholic educators and meet with leaders of other faiths.