Benedict, 81, hopes that the longest trip of his Pontificate, which culminates in Sydney's World Youth Day celebrations, will reinvigorate a moribund Australian Catholic church youth festival, begun by his predecessor Pope John Paul II in 1986, and last held in Cologne in 2005.
But even as he was welcomed by Kevin Rudd, the Prime Minister, local Catholic leaders sought to minimise the fallout from a sex abuse case and criticism of tough new police powers to protect pilgrims from "annoyance" by critics of the church.
During his flight from Rome, the pontiff said he would "apologize" to sex abuse victims, as he did during a visit to America in April. "We have to see what was insufficient in our behaviour and how we can prevent, and heal, reconcile," he said. “It must be clear, being a priest is incompatible with this behaviour because priests are in the service of our Lord.”
Leaked documents last week deeply embarrassed the Pope's friend and Australia's most senior Catholic, Cardinal George Pell, who admitted to a mistake in a "badly worded" letter written in 2003 to a man who claimed to have been sexually assaulted by a priest in 1982. The Cardinal wrongly told him an inquiry had not upheld his complaint.
Cardinal Pell has been forced to admit he may have been wrong to believe the priest's claim that the sex had been consensual, and has opened a new inquiry into the abuse. Campaigners say there have been107 convictions for sexual abuse within the Church in Australia but say that this masks the true scale of the problem.
Broken Rites pressure group said that the papal apology needed to be specific and meaningful. "We want the Pope to force Cardinal Pell and all Australian bishops to be more transparent and less evasive when handling complaints from victims," a spokesman, Dr Bernard Barrett, said.
“We continue, the church here in Australia, to be committed to doing all we can to bring healing to the victims of sexual abuse,” said Bishop Anthony Fisher, the coordinator of World Youth Day.
Benedict also expressed his intention to "wake up consciences" on climate change. While refusing to debate the science of global warming, he said "we have responsibilities towards creation". His is a topical message in a nation watching its greatest river system die in the worst drought on record.
The Pope will spend his first three days in Australia at an Opus Dei retreat. On Thursday he will visit to the tomb of Mary MacKillop. Benedict's predecessor declared the Australian nun 'blessed' in 1995 and she now needs official confirmation of a second miracle to become Australia's first saint.
He will also take a Sydney Harbour boat trip, a helicopter ride, and meet disadvantaged young people and aborigines. The celebrations incorporate old and new - from a collection of saintly bones to daily papal text messages, and 165 rock, rap and jazz concerts. The highlight will be a mass next Sunday at the city's racecourse, hoped to attract 500,000 people.
The Pope's focus will be on the under-35s he believes hold the key to renewal of a church "in crisis". He will urge them to embrace the Holy Sprit and push back the "tide of secularism".
The octogenarian faces a challenge connecting to youth, especially in Australia, which he previously singled out as a nation where the church is dying. In the decade to 2006, the number of Christians fel from 71 per cent to 64 per cent.
While 5.1 million Australians claim to be Catholic, no more than 800,000 regularly attend church. The priesthood is in decline and ageing, with numbers down 20 per cent since 1971 and the average age up from 44 to 60. Only 141 were in training in 2005, a quarter of the number in 1969.
In hedonistic Sydney, home to one of the world's biggest gay and lesbian Mardi Gras, not everyone is sympathetic.
While the New South Wales Government has extended police powers to arrest and fine people for "causing annoyance" to World Youth Day participants - with fines up to $5,500 - that hasn't stopped locals printing shirts with messages like "Pope go Homo".
Organiser Bishop Anthony Fisher said the hostile reception was confusing pilgrims.
"It's a pity that sometimes there's been a lot of negativity in the air - some of our pilgrims are coming saying, `What's going on here? This is the most wonderful thing for your country and for your church, they should be happy like we are,'" he said.