Finding the path to "a new beginning for common mission in the 21st century" is the challenge put before participants at an international conference on the past and future of Christian mission taking place in Edinburgh, Scotland, from 2-6 June 2010.
The international gathering commemorates the hundredth anniversary of the 1910 World Mission Conference which took place in the same city and which is widely considered the symbolic starting point of the modern ecumenical movement as well as many twentieth century initiatives in European and global Christian witness and service.
"One hundred years after the Edinburgh conference in 1910 we are challenged to launch together a new beginning for common mission in the 21st century", the World Council of Churches (WCC) General Secretary, the Rev Dr Olav Fykse Tveit told conference participants on 3 June.
Tveit was one of two speakers expressing hopes and expectations for the conference before some 300 delegates from over 60 countries and virtually all Christian traditions at the opening celebration.
The other key speaker was the Rev Dr Geoff Tunnicliffe, international director of the World Evangelical Alliance. He said he hoped that the Edinburgh 2010 conference will help participants to achieve a "renewed commitment to bear witness to Christ with the love of the Father and in the power of the Holy Spirit in every corner of the globe".
The WCC General Secretary emphasised the need for contemporary Christian mission to reconcile 'evangelisation' (the sharing of the Gospel message through life, word and deed) and 'prophetic witness' (addressing the causes of injustice and division through action for peace and justice rooted in a vision of God, people and the world living in harmony).
"It is important to keep a healthy dialectic and creative tension between the many dimensions of our calling", Tveit said. "To witness to Christ is both evangelism and the prophetic stand for Christ's will for justice, peace and care of creation", he added.
Tveit also highlighted that mission and unity are inseparable: "Mission and unity belong together. To be one in Christ is to witness together to Christ."
Tunnicliffe said that although it would not be realistic to expect historical differences to be solved in a few days, he hoped "that during the conference participants will be able to "listen to one another with love and respect, build bridges rather than create chasms, pray together, learn together, establish new friendships".
"We come to celebrate the progress of world Christianity over the last 100 years", Tveit said. Amongst some "difficult lessons" that have been learnt during that period, he mentioned "the links between mission and colonialism", "shameful power struggles" and the fact that "mission is a challenging theme in our relations to people of other faiths".
Tveit acknowledged that "many more sectors of world Christianity now take their inspiration from the deliberations of the 1910 Edinburgh conference than those who actually participated in the event". Therefore he emphasised: "Nobody needs triumphalistic movements and churches. The world needs faithful disciples of Christ, always carrying the cross in love and solidarity with the world for which Christ died."
The 1910 World Mission Conference brought together some 1,200 representatives mainly linked to the Western missionary movement. In addition to its focus on evangelism, the historic gathering emphasised cooperation and unity.
The Edinburgh 2010 conference gathers with the theme 'Witnessing to Christ today' and is hosted by the School of Divinity at the University of Edinburgh. The World Council of Churches (WCC) supports its organisation, together with partners in the ecumenical movement, within and beyond the WCC fellowship.
The wide spectrum of churches, denominations and mission traditions united around the project makes it one of the most representative of the diversity of world Christianity today. This spectrum includes Orthodox, Anglican, Lutheran, Reformed, Methodist, Baptist, Seventh Day Adventist, Roman Catholic, Evangelical, Pentecostal and Independent traditions.
The conference will end on Sunday 6 June, when participants will join members of the local churches and gather at the 1910 Assembly Hall for "a significant celebration", the organisers have announced.
In parallel to the centenary conference, a plethora of workshops, events and services are being organised by local churches and organisations all over the world. A multi-denominational and international study process has been carried out in order to provide new perspectives on mission for the 21st century.
Edinburgh 2010 website: http://www.edinburgh2010.org/ 
With thanks to the WCC media team