Surrounded by palm and olive branches, Pope Benedict led the Roman Catholic Church towards the first Easter season of his pontificate today and said selfishness and corruption were devastating today's world.
Benedict presided at a Palm Sunday service in St Peter's Square to commemorate Christ's triumphant entry into Jerusalem, when he was welcomed by adoring crowds a week before people turned against him and he was arrested and crucified.
This year marks the first Easter season for Pope Benedict. His predecessor John Paul was in his dying days for all of last year's Easter season and was only able to make brief appearances in the week between Palm Sunday and Easter Sunday.
John Paul died on April 2, a week after Easter.
Speaking on a brilliantly sunny day to tens of thousands of people, the Pope weaved his sermon around the contrast between material and spiritual riches and the relationship between personal freedom and responsibility.
After blessing palm and olive branches -- symbols of peace -- he called for people around the world to undergo "a purification of hearts" to help heal what he said was a "lacerated world".
He urged them to look to Christ for help to "overcome the corruption and selfishness which is devastating the world today".
Christ's message, he said, was "not to respond to an injustice with another injustice, to violence with another violence, but to remind us that evil can only be overcome with good, not with another evil."
Palm Sunday also marked this year's World Day of Youth, which is held in local dioceses each year and at an international venue about every three years in the presence of the Pope.
The last international day was in August in the Pope's native Germany; the next will be in 2008 in Sydney, Australia.
The Pope, wearing red and white vestments, urged young people not to give in to the temptations of worldly riches and moral irresponsibility.
"All this sounds convincing and seductive but it is the language of the serpent," he said, referring to the Biblical story where Eve was convinced by the devil in the form of a snake to disobey God.
At the service, young people from Germany handed over to those from Australia a large wooden cross to take to Sydney.
The Pope said their journey would symbolise their attempt to spread peace "across continents and cultures, across a world lacerated and tormented by violence."
The 78-year-old Pope will have a hectic week ahead of him as he leads Roman Catholics to Easter.
He hold his general audience on Wednesday.