VATICAN CITY, JULY 18, 2007 (Zenit.org).- The next Week of Prayer for Christian Unity will mark the 100th anniversary of this event.

"Pray Without Ceasing," is the theme for the 2008 week, traditionally held in the northern hemisphere Jan. 18-25 and jointly prepared by The Pontifical Council for Christian Unity the Commission on Faith and Order of the World Council of Churches.

Those two organizations recently released the guidelines for the upcoming week, which includes an evaluation of the event's 100-year history.

"We can speak of the history of the Week of Prayer as one of success. It is a source of great joy and profound gratitude," the document states.

The text, published on the Internet in various languages, gives a historical overview of the week.

It also explains the motivation for the 2008 theme: "The text 'Pray without ceasing' -- 1 Thessalonians 5:17 -- stresses the essential role of prayer within the life of the Christian community as its members grow in their relationship to Christ and to one another.

"This text is one in a series of 'imperatives,' statements in which Paul encourages the community to live out its God-given unity in Christ, to be in practice what it is in principle: the one body of Christ, visibly one in that place."

The text also includes guidelines and models for prayer services to be held during the week.

ZE07071806 - 2007-07-18