CHICAGO — In one busy late-July week, Mel Gibson promoted his film The Passion to Catholic leaders and journalists in New York, Washington and Chicago. But none of the audiences he assembled matched his July 18 appearance at the Regnum Christi Youth and Family Encounter on Chicago's Navy Pier.

The July 17-20 event, a combination apostolic convention and pep rally, was attended by nearly 5,000 Catholics. On the second evening of the four-day event, Legionary Father Owen Kearns, publisher of the Register, announced a “surprise” guest and Mel Gibson came to the podium.

Pulling a rosary from his pocket, Gibson said, “Nothing is more powerful than prayer.”

The passion of Christ was one of the themes of the Youth and Family Encounter that included concerts, how-to talks on evangelization and separate events for children.

Immediately following Gibson, keynote speaker Sen. Rick Santorum, R-Pa., spoke of policy issues regarding family and culture.

On abortion, he said the American rights to “life, liberty and the pursuit of happiness must come in that order.” He said Americans should oppose abortion not on a religious basis but because the “right to abortion” distorts this country's founding principles “by putting the mother's right to liberty ahead of her baby's right to life, which is never justified. The right to life must always be primary,” he said.

“There is nothing quite like seeing so many Catholic families who are so committed to their faith that they feel they ‘must’ do something more for Christ,” said Mary Ann Yep, a mother of eight and one of the key organizers of the Chicago event. “It was a challenge, but ever so worth it, knowing that thousands of people will return to their cities and parishes ready and motivated to continue serving the Church.”

Regnum Christi, Latin for “Kingdom of Christ,” is one of the new ecclesial movements Pope John Paul II has hailed as a “sign of the springtime of evangelization foretold by Vatican II.” In the United States and Canada, the movement currently numbers more than 8,000 lay members.

The weekend culminated in a Mass celebrated by Bishop Thomas Paprocki, auxiliary bishop of Chicago, who said he hopes to see Regnum Christi spread throughout the archdiocese and the world.

The Chicago encounter took as its theme Christ's words to Peter in a similar lakeside setting: “Cast your nets.” Evan Lemoine, a Regnum Christi member from Louisiana now beginning a year of service to the Church as a co-worker, shared his testimony and said, “If every single one of us casts out our nets at our schools, our workplaces, our families, our neighborhoods … we would change the world for Christ.”

The Youth and Family Encounter began with a focus on the Passion. The audience was given an eight-minute peek at a video being produced by Dr. Thomas McGovern, a physician from Indiana. The video, When God Died, explains the medical reality of Christ's passion and puts it in its spiritual context.

“It leads us to appreciate more and more just what Christ went through for us,” said Gregg Backstrom, a Regnum Christi member from the Minnesota who is involved in ConQuest clubs and camps for boys.

The video was fallowed by an appearance from Steve McEveety, producer of several Gibson films, including The Passion, who explained what filming the story of the last hours of Christ's life has meant to him. “Everyone involved has come away a different person, myself included,” he said. “I don't care if the movie doesn't make a penny. It had to be done.”

He played an extended trailer of the movie.

Other highlights of the weekend included a talk by Rev. Jerry Kirk on the dangers of pornography. Kirk is a Presbyterian minister from Cincinnati and the co-founder with the late Cardinals John O'Connor and Joseph Bernardin of the Religious Alliance Against Pornography.

In Catholic circles Kirk is widely known as the father of Kimberly Hahn and father-in-law of theologian Dr. Scott Hahn. Kirk began his presentation on the scourge of pornography in society by quoting several inspirational passages from Christ Is My Life, the new book-length interview of Father Marcial Maciel, founder of the Legion of Christ and Regnum Christi. Kirk, who had received the book only the day before, said he stayed up into the wee hours reading it. “This book is a blessing to me,” the noted Protestant leader said.

Past Youth and Family Encounter events have featured Father Maciel. He was unable to attend the Chicago event, but in his place the event featured a presentation by Jesus Colina, director of Zenit news agency and the interviewer of Father Maciel for the biographical book, Christ is My Life.

In one extended session, Father Anthony Bannon, territorial director of the Legion of Christ and Regnum Christi in North America, then announced the most ambitious apostolate yet undertaken by the Legionaries and Regnum Christi in this territory: the University of Sacramento. The crowd cheered on the new university, waving pompoms and singing the school's fight song.

But the biggest cheer of the evening came when Father Kearns returned to introduce Mel Gibson. The actor spoke briefly about how he met the Legionaries while filming The Passion in Italy.

“I'm not a preacher, and I'm not a pastor,” Gibson said. “But I really feel my career was leading me to make this. The Holy Ghost was working through me on this film, and I was just directing traffic. I hope the film has the power to evangelize. “

He then offered to take questions from the audience, including a 10-year-old boy's question: “Can I shake your hand?” Gibson agreed, and the crowd cheered as the boy made his triumphant return to his seat, both fists raised high above his head.

Another questioner asked why The Passion “ is spoken in dead languages instead of English.” Gibson answered with a pointed question: “Have you seen the versions done in English?”

Jay Dunlap contributed to this article.