After years of preparation and anticipation, World Youth Day Sydney 2008 (WYD08) commenced with a spectacular Opening Mass celebrated by Cardinal George Pell at Barangaroo.

After Pope Benedict XVI sent a personal text message to pilgrims, the atmosphere in the Sydney city was electric.

He sent: "Young friend, God & his people expect much from u, because u have within u the Father's supreme gift: the Spirit of Jesus - BXVI"

Approximately 150,000 pilgrims attended Barangaroo and other CBD live sites for the Opening Mass.

The warm weather and gorgeous Sydney harbour as a backdrop left the crowd in awe as the sun went down during the proceedings.

After an official indigenous welcome, Prime Minister Kevin Rudd inspired the crowd when he said "too often when young people travel in large numbers, it's for war. But you have come here as pilgrims of peace."

Following the 168-flag procession and the walk-in of the WYD Cross, Icon and Indigenous Message Stick, Cardinal Pell welcomed the international pilgrims in four languages - English, French, Spanish and Italian.

Joined by 26 Cardinals, 400 Bishops, a 300-person youth Choir, and an 80-piece orchestra, his Homily focused on the fruitfulness of commitment.

"Don't spend your life sitting on the fence, keeping your options open, because only commitments bring fulfilment.Happiness comes from meeting our obligations, doing our duty, especially in small matters and regularly, so we can rise to meet the harder challenges," he said.

In one of the closing speeches, Cardinal Stanislaw Rylko created a new feeling when he stated that the WYD08 pilgrims have brought Spring to the Australian Winter, and a new Spring time for the Australian Church.

Earlier in the day, Australian Military pilgrims gathered with their Bishop Max Davis at the Sydney Opera House for a performance for visiting pilgrims.

The Vocations Expo at the Sydney Convention and Exhibition Centre officially opened today, featuring over 100 exhibitors from all over the world.