Scenes from the World Meeting of Families opening

Families from all over the world waved their native flags, clutched their babies, and cheered during Tuesday's opening ceremony for the World Meeting of Families.

"It has begun - the start of the most historic event in modern Philadelphia history. . . . I want to welcome the joyous pilgrims here to our great city," Mayor Nutter told the tens of thousands gathered at the Convention Center. Choirs sang, schoolchildren played bells, and gifts were presented during the nearly hour-long pageantry.

Tuesday marked the first day of the four-day conference, whose theme is "Love Is Our Mission: The Family Fully Alive." The conference workshops, which touch upon various topics, end Friday, just before Saturday's highly anticipated arrival of Pope Francis in Philadelphia.

Most of the families attending the conference will also be at Independence Mall on Saturday for Francis' speech on immigration, and on the Parkway on Sunday for the papal Mass.

Although many attendees had traveled thousands of miles to get to Philadelphia, few were displaying jet lag.

"A very good welcome," Lourdes Bicudo of Uruguay said in Spanish of the opening event.

The excitement pulsed through the crowd at the Convention Center. Many wore their country's flags and some groups broke out in songs or dance.

Six students, each representing one of the local Catholic schools in the region, held up signs during the opening ceremony, showing where some of the congress attendees hailed from: the Philippines, Vietnam, Nigeria, Argentina, Idaho, and, last but not least, Pennsylvania (specifically, Wayne). The children then played a melody on Schulmerich handbells.

Nutter, Archbishop Charles J. Chaput, Archbishop Vincenzo Paglia - the Vatican's head of the Pontifical Council for the Family - and World Meeting of Families organizers spoke of the importance of family during the event.

"The family is our most valuable and most important resource. . . . If family is stronger, society itself is stronger," Paglia said.

Paglia encouraged those attending the conference to discuss the challenges facing families today and help one another, ending with, "My dear friends, your work awaits you."

Sister Theresa Lee, 47, from Salesians of St. John Bosco in North Haledon, N.J., searched for her group at the opening Mass for the World Meeting. She looked at the thousands gathered to worship.

"This is just what our country needs," Lee said. "Families need support morally and spiritually."

The gathering of families from different parts of the globe is a testament to how faith can unify, she said. Lee was accompanied by six eager candidates looking to initiate themselves as Salesian sisters.

"I see young women searching for a deeper relationship with Jesus and looking to give themselves in service to others in a life where sacrifice still has value and meaning," she said. "Women have always had an essential and critical role in the church."

The controversy that has surrounded Margie Winters, the Waldron Mercy Academy teacher who was fired after two parents complained about her same-sex marriage, found its way into Chaput's morning news conference.

Chaput, who has backed Winters' dismissal, was asked to comment about news that Winters and her wife, Andrea Vettori, had been invited to the White House for Francis' arrival ceremony. The couple are hoping to plead their case to the pontiff.

"Who the president decides to invite to the White House is up to him," he said, adding that he did not believe that Francis would comment on the matter.

Later, Paglia was asked about the church's stand on LGBT families.

Paglia said that each person has dignity and is a saint loved by God, but that family is meant "as a man and a woman . . . and we have to obey the Holy Scriptures."

When Francis arrives in Philadelphia in a few days, he will be greeted by hundreds of thousands of people - and one tool to maneuver around them all if he wishes to: a custom-made bike.

During the opening ceremony, Nutter presented the bicycle and a china bowl that will be given to Francis.

The gift are "of practicality and elegance for a humble and inspiring leader," Nutter said.

The description of the bike, which is has eight speeds and a leather seat, drew laughter from the crowd.

Among the emblems it bears are "Papa Francisco" on the top rail, the pope's crest, a cross, and a peace sign. As a tribute to Philadelphia: a Liberty Bell and a "PHL Made" logo.

Nutter's favorite part of the bicycle: the angel-wing cutouts on the chain guard.

"This bike was created to celebrate Pope Francis' advocacy for environmentally responsible modes of transit," said Nutter, an avid cyclist.

The city also donated 100 bicycles to bicycle community programs in Philadelphia in the pope's honor.

The other gift is a handcrafted ivory bone china bowl with a 24k gold border. The bowl was custom made by Lenox, based in Bristol.

Waving the flag of Zimbabwe, Emelda Mandando posed with the pope's bike. Francis is "so different from other popes," she said, she is sure he is going to ride it.

And now she can say she touched the holy bike and has the picture to prove it.

"He's a man of the people," Mandando said, echoing Nutter's words. Mandando, traveling with her countrywoman Silvia Duri, said Philadelphia has been great so far.

"I like the part when the mayor said Philadelphia is a brotherly city," Mandando said.

Duri added: "We proved it yesterday."

The women, who are staying in Malvern, were at the train station Monday trying to figure out how to get to Center City when a local couple offered them a ride. They didn't catch their benefactors' names, but said they'll never forget the gesture.

Treena Ferebee and the choir from Praise and Glory Tabernacle in Southwest Philadelphia so pumped up the audience at the opening ceremonies, Chaput broke through the crowd to embrace her.

Then, the pilgrims who traveled from around the world surrounded Ferebee for photos.

Myriam Mwangi, 36, of Kenya, put her arm around the singer. The family life coordinator for the Archdiocese of Nairobi said the music during the ceremony had moved her to tears.

"Amazing," she said.

Decked out in orange hats and outfits made of fabric emblazoned with images of Robert Indiana's iconic LOVE statue and the World Meeting emblem, Sinaisiwe Blandia Makumure and her husband, Fastino, took in Tuesday's opening ceremony.

The couple are here as part of a group of 30 people from Zimbabwe. The Makamures are excited to see Francis this weekend but are also looking forward to the workshops.

"We want to strengthen our faith through seeing united families, show love for the church, for the families and for everyone," Sinaisiwe Makumure said.