The groups also will open contacts with Islam and other faiths to study ways to avoid conflicts.
"We hope to produce a code that will ensure that believers commitment to their faith never translates into denigration of another," said Hans Ucko, head of the 348-member WCC's Office on Inter-religious Relations and Dialogue.
The three-year study project- called "Interreligious Reflection on Conversion: From Controversy to a Shared Code of Conduct"- had arisen several years ago during regular contacts between the Geneva-based WCC and the Vatican after methods used by Christian missionaries in India had caused problems for local Christians.
Religious freedom and missionary outreach by Christian groups have become increasingly sensitive topics as many Muslims perceive their faith as under threat by the West and nations such as China struggle to maintain state controls on churches.A recent controversy includes Pope Benedict defending a 40-year-old Afghan facing a death sentence in Kabul for converting to Christianity.
The man, Abdur Rahman, was freed from jail to condemnation from many Muslim clerics after intervention by Western-backed President Hamid Karzai, and now lives in Italy.
“This is basically an intra-Christian project, a dialogue between Christians, because although some take a low-key approach others embark on what can be seen as crusading which offends people of other religions," said Ucko.
"The issue also touches on religious freedom," he added. "In the world we live in today, changing one's religion should not be seen as a betrayal of Islam or of any other faith."
