Pope Benedict has led hundreds of thousands of pilgrims in a giant mass, ending a week of World Youth Day festivities, which was marked by an historic papal apology for sex abuse.
The final service at a Sydney racecourse came a day after he said he was deeply sorry for the sexual abuse of children in Australia.
The Pope said people should build a new age free of greed, apathy and selfishness.
The pontiff also announced that the Catholic Church will hold its next World Youth Day in Madrid in 2011.