Thousands of Christians from 68 nations representing 19 denominations have gathered at the Acer Arena in Sydney, Australia to take part in the five-day annual Hillsong Conference.

Considered Australia's largest annual conference, each year it attracts pastors, worship leaders, musicians, community workers and individual believers representing hundreds of churches.

"The mandate of the conference is, and has always been, to champion the cause of the local church," Senior Pastor of Hillsong Church, Brian Houston said.

"It is this cause that attracts people from around the world, and it's a message that transcends geography, culture and denominations."

More than 70 per cent of delegates are from Australia, but some delegates travelled from as far as Macau and Kazakhstan, with a significant number coming from the US, South Africa and Singapore.

Some of the most famous church leaders and Christian musicians will join the Hillsong team again this year including Grammy Award winner Steve Curtis-Chapman, and Chris Tomlin, whose song 'How Great is our God' reached number one on the Christian Billboard Charts. Best-selling author John Bevere and the Reverend TD Jakes will join.

Houston said: "We are truly honoured to host this conference. It's difficult to believe that all this started with 150 people in a small hall in Castle Hill two decades ago!"

He added: "We never take for granted the commitment and effort it takes for people to position themselves here. Our aim is to equip, inspire and empower people and churches to make a positive difference in their communities."

The word 'justice' and the responsibility it infers is one of the key messages that will be promoted across the breadth of the conference.

Delegates will hear from Pastor Gary Skinner and the Watoto Choir about the plight of Aids orphans and child soldiers in Africa, and Wes Stafford, CEO of child sponsorship organisation Compassion, will encourage people to change a child's life.

"God tells us that standing against injustice and speaking up for the disenfranchised is the responsibility of every Christian. The conference will help highlight the impact we can make if collectively we decide to take this responsibility seriously."