Porto Alegre, Brazil - The forces reshaping Christianity come with many names.
In Nigeria, the Mountain of Fire and Miracles congregation holds huge all-night revivals. Across Asia, the True Jesus Church preaches biblical interpretations that include shunning Christmas as a pagan-tainted holiday. In Brazil, the Universal Church of the Kingdom of God says rewards -- spiritual and material -- may await those who give to its fast-expanding empire.
Such ways of worship that challenge the dominance of Christianity's mainline denominations on every continent will be high on the agenda this week as envoys from the faith's main branches gather in Brazil for their most ambitious conference in eight years.
The World Council of Churches hopes to leave its assembly in Porto Alegre, starting Tuesday and running through Feb. 23, with a clearer vision of how to address the sharp growth of Pentecostal, charismatic and evangelical groups around the globe.
The head of the council, the Rev. Samuel Kobia, will urge delegates to fully recognize the spiritual shifts and begin serious dialogue with Pentecostal and other groups, who have often regarded the WCC as a threat to their independence, fundraising methods and animated worship style.
''We need a fresh look at global Christianity,'' Kobia told The Associated Press from the WCC headquarters in Geneva, Switzerland. ``I will also call on Pentecostals, charismatic and others to approach us in an open mind and not with the hostility of history that has led to suspicion.''
Still, it's the WCC that needs to reach out. The core of its nearly 350-church membership -- the mainline Protestant denominations and Orthodox churches -- have felt the full force of the rise of Pentecostal and other movements.
More cooperation could energize some old guard denominations and help stem defections to evangelical-style churches, particularly in Africa and Latin America. Failure to find more common ground, however, could reinforce polarizing trends: the traditional churches vs. movements preaching bold messages of salvation and, sometimes, good fortune.
Among the most attention-grabbing has been the so-called ''the Gospel of prosperity'' -- independent pastors proclaiming that God favors the generous. Critics claim it's simply a way to fill collection baskets and enrich preachers.
The other lure of the new churches is passion: local music, dancing, testimonies of miraculous healings, speaking in tongues and offering prophesies. Many Protestant and Roman Catholic churches have answered by integrating practices popular among Third World Christians, but can't make changes to the basic elements of worship. (The Catholic church is not a WCC member, but cooperates closely on many levels and will send representatives to this month's conference.)
The Pentecostal movement goes back more than 150 years and inspired later evangelical and charismatic offshoots in established churches. Recent decades, however, have witnessed sustained growth as nontraditional Christian churches get larger and more organized with outreach such as television ministries and Internet sites.
Such churches have nearly 597 million followers, or more than a quarter of Christianity, and are expected to grow to more than 783 million by 2025, according to the Center for the Global Study of Christianity in South Hamilton, Mass.
''I think it is now evident very clearly that there is very fast growth of Pentecostal and charismatic and some conservative evangelicals in all parts of the world, but especially in what is called the global south,'' Kobia said. ``They are simply drawing Christians from existing congregations . . . This has caused tensions.''
Representatives from more than 50 Pentecostal and charismatic churches are expected at the WCC meeting as observers. But experts say they are unlikely to exert any significant pull.
''If you were going to have contact with WCC, you are already on the margins of evangelicalism,'' said Scott Thumma, a professor of religion and sociology at the Hartford Institute for Religion Research.
The gathering -- the first of its size for the WCC since 1998 in Zimbabwe -- will also will be forced to look at troubles within: rifts over same-sex unions and homosexual clergy that threaten the unity of several pillars of the council including the Anglicans and Lutherans.
Kobia said the specific disputes were not on the agenda, but could be addressed if raised by delegates. Among the expected participants is the archbishop of Canterbury, the spiritual leader of the world's Anglican Communion, a body badly split along Western and Third World lines over the place of gays in the church and other issues.
The WCC also is expected to explore methods for expanded contact between Christian groups and moderate Islamic leaders, which has taken on urgency following the widespread violence by Muslims protesting the publication in Denmark and elsewhere of cartoons depicting the Prophet Muhammad.
Other talks at the meeting will seek to move the Vatican and WCC closer on efforts such as interfaith outreach and social issues such as international debt relief.