Evangelical Christians convening in South Africa this October for the Third Lausanne Congress on World Evangelisation will adopt a new document following in the footsteps of the historic Lausanne Covenant that exhorted Christians to preach the good news to all mankind.

The document, entitled the Cape Town Commitment, will be "rooted in the centrality of the uniqueness of Christ, and on the authority of the Scriptures", the Lausanne movement said.

It will reflect discussions of some 4,000 evangelical leaders from 200 nations who will gather at Cape Town from October 16 to 25. The gathering will relate to the future of the Church and evangelisation in the 21st century.

Lindsay Brown, International Director of The Lausanne Movement, said the statement would provide evangelicals with a clear definition of the nature and call of the church.

"There is a lack of clarity when we talk about evangelism and the gospel, particularly in the Western Church. We need to have agreement on the message we are proclaiming," he said.

Brown said he hoped the Cape Town 2010 would result in a "fresh call to the Church worldwide to bear witness to Jesus Christ and all his teaching in all of the world – not only geographically, but in the sphere of ideas".

Chris Wright, Director of Langham Partnership International, will be the chief architect of the Cape Town Commitment.

Doug Birdsall, Executive Chair of The Lausanne Movement, said: "This is a critical moment for the global Church, with pressures from outside and dissension within. We trust the Cape Town Commitment will be a clarion call for unity around the primary truths of the Gospel.”

The Cape Town Commitment will stand in the line of the Lausanne Covenant (1974) and the Manila Manifesto (1989). John Stott was the chief architect of both documents.

The Lausanne Covenant has been translated into 20 languages and adopted by evangelicals around the world as their "statement of faith", making it one of the most influential documents in modern evangelical Christianity.