Do the World Youth Day (WYD) pilgrims come for the religion or the showbiz?
Or is it just to have a good time?
According to pilgrims who have made the long journey Down Under, WYD discards the musty confines usually associated with the church, allowing them greater control over how they celebrate their faith.
Asked what drew him to Sydney for the event described as a "Catholic Woodstock", German man Martin Langert said WYD cast a young face on a centuries-old religion.
"What I like about World Youth Day is that usually the church is crowded with older people and it is sometimes boring - I noticed at the last World Youth Day that you have so much good energy, and fun, and you meet so many nice people," the 27-year-old electrical engineer said.
"It's being in the church, but in a different way.
"You're celebrating mass in a different way and it makes your beliefs stronger."
The inspiration for World Youth Day came 25 years ago, early in the reign of Pope John Paul II, when for two years running, an "ocean" of a quarter of a million young people attended special Palm Sunday youth masses in St Peter's Square.
"I have, imprinted on my soul, the festive image of their enthusiasm," the Pope said at the time.
"I am hoping that this wonderful experience might be repeated in future years, giving origin to World Youth Day on Palm Sunday."
John Paul II had established a new practice in the Catholic Church.
Mr Langert said the Catholic Church's pitch to young people should happen more often, and at a local parish level.
"The people who come to the parish after World Youth Day, they bring a piece of it back with them," he said.
"I think the church will change, because it has to open in different ways to modern things to keep modern. The church will change because they want to stay close to the people."
Sydney's Catholic Archbishop, Cardinal George Pell, made great play in his opening mass of the imagery of one "lost sheep" in a hundred.
He directed his words not at the 99 sheep who had found comfort in God but at the one that had lost its way, "in deep distress with hope diminished or even exhausted".
Despite most people associating young people with frivolity, and the worship of all that is new, Pierre Konja from the United States said the church filled a hole left vacant by a consumerist, secular society.
"People try to fill the gap in their lives with anything from sex to work or success, but you really can't fill that gap in your soul," said the 22-year-old, who is studying to be a priest.
"Why are we here? Why do we exist? Where are we going? These are important questions that the church can provide answers to."
World Youth Day was part of the constant renewal of the church, Mr Konja said, with organisers adapting to the tech savvy ways of young pilgrims in just one example. "It is always renewing itself," he said. "It will never change its teachings, but it's adopting modern technology -- everybody here had to register on internet.
"They're using the modern technology to spread the gospel. You can go on the internet and find whatever you want."
The Pope has even sent a religious text message to pilgrims every day of this WYD festival, signing off as BXVI.
Canadian philosophy student Joseph Nugent said WYD gave young people a chance to escape the "go-go" pressures of Western society.
"The answers that they (secular society) have aren't making me happy, aren't giving me joy," the 20-year-old said.
"At this gathering we're taking time to slow down from that here and now.
"This is giving us a chance to hear ourselves think, and hear what other youth are like, as opposed to going out and getting drunk or smoking away."
The coming together of so many people also gave pilgrims the chance to debate and discuss some of the weighty issues plaguing the planet -- and of concern to young people regardless of their beliefs -- such as the environment and social justice.
"World Youth Day provides a venue to talk about these issues with other young people," Mr Nugent said.
"It's wonderful that we can talk to anybody about just about anything - our beliefs and our struggles in life.
"I think the main focus is just to get us together to allow these kind of issues to come out and get us talking."
But WYD was not just about weighty religious discussions - it was also about having a good time, he said.
"We have so much fun through all the different activities. We have a blast," he added.
Perth teenager Jacob Diamond, who travelled to Sydney with his local parish group, said WYD would change the non-Catholics' view of how the church celebrated its faith.
"This is just how young people are," the 15-year-old said.
"Can you imagine if all we did is go to church and then hung out in our room? It wouldn't be too much fun.
"It's a great thing for non-Catholics to see. We're not just a bunch of hard-arses that just go to church on a Sunday and pray all the time."
Asked if he would go to the next WYD, likely to be held much further from home, Jacob said: "Hell yes."
"Cost is not a factor," he said.
"They need to do things like this to keep it vibrant and attractive for the youth."
