Missionaries also evangelized regions throughout Southeast Asia and the Pacific. The first missions to Vietnam were undertaken in the 16th and 17th centuries by Dominicans and Jesuits from Portugal and France. A more permanent presence, which led to French military intervention, was established in the 18th and 19th centuries. In the early 21st century some 9 percent of the population of Vietnam was Christian.

Dutch chaplains established churches in Indonesia in the 17th century. In the mid-19th century the German Rhenish Missionary Society enabled the Batak Church of Sumatra to grow in size and strength and to provide leadership for the nation. Other strong churches developed in various parts of the predominantly Muslim country.

The vast Pacific Ocean, with tiny, scattered island kingdoms among the Polynesian, Micronesian, and Melanesian peoples, early attracted missionaries. Most of them were laypeople of deep Christian faith. It was the effort of the Christian islanders, however, that achieved virtually total evangelization of the Pacific.

Missions to Africa and South America

Although Christianity had existed in Ethiopia since the 4th century, much of Africa remained a mission field into the 20th century. Protestant missionaries were working in most of the West and Central African colonial nations in the 19th century, but in some parts of East Africa mission began only in the 20th century. After Ghana gained freedom in 1957, many former colonies were granted independence. Cataclysmic change appeared everywhere: in building new nations; rapid shifts from a rural to an urban population; coping with the massive problem, especially in cities, of some 2,500 languages; and developing literacy. Amid all this, Christianity grew with increasing rapidity. By the early 21st century more than half of the sub-Saharan African population was Christian. African independent, or indigenous nonwhite, churches proliferated, and several of the largest ones joined the World Council of Churches.

In the 19th century Evangelical churches were begun in Latin America by Protestant missionaries who were largely from the United States but also in some instances from Britain and Germany. Most of these churches have remained small. The exception was the explosion of Pentecostalism throughout the region, with heaviest concentration in Brazil, Chile, and Mexico. Evangelicals also have gained members in Central America.

Missionary associations

Protestants discovered the need for cooperation and unity. As tiny minorities in lands of other religions, new Christians and missionaries together saw that denominational separatism hindered evangelization. Four streams led to the cooperation and unity reflected in the World Missionary Conference (WMC) held in Edinburgh in 1910. First, missionary “field” conferences affirmed comity (separation of spheres of work), cooperation in Bible translation and missionary councils, and shared sponsorship in major enterprises such as hospitals and colleges. A second stream involved missionary conferences in England and the United States from 1854 to 1900. A third force flowed through the missionary concern of the international student Christian and missionary movements. The fourth stream arose in the West from continuing interdenominational conferences of mission leaders to face common concerns and forge common policies. Among others, these included the Continental European Missions Conference (1866) and the Foreign Missions Conference of North America (1893).

The Edinburgh conference was unique—a landmark and watershed for all that was to follow. Largely Western in membership, but with 17 Asian delegates, it created a Continuation Committee that in 1921 became the International Missionary Council (IMC). The IMC consisted of a worldwide network of Christian councils and the Western cooperative agencies. In 1961 the IMC became the Division of World Mission and Evangelism of the World Council of Churches (WCC). In 1971 the Division underwent further restructuring but maintained its relationship with the WCC and in the late 20th and 21st century sponsored a series of ecumenical conferences on world mission.