When the World Mis­sionary Con­ference gathered in Edin­burgh in 1910, it would have taken real optimism to identify Korea as a prospect for major Christian growth. At that point, Christians made up perhaps 1 percent of the Korean people, and the nation was under the heavy-handed occupation of Japanese author­ities, who looked dimly on Western cultural intrusions.

Through the 20th century, though, Christian growth in Korea has been astonishing. At least 30 percent of South Korea's 50 million people are Christians. Some of Seoul's spectacular megachurches regularly appear in listings of the world's largest congregations; they are virtually denominations in their own right. The best known is the (Pentecostal) Yoido Full Gospel Church, which claims 850,000 members.

The Myung Sung Pres­by­terian Church is the world's largest congregation in that tradition. Korea has more Presbyterians than the U.S. does. After the U.S., South Korea is the world's largest supplier of Christian missionaries. This Christian activity developed in one of the world's industrial and financial powerhouses, with huge media assets. When future scholars write the history of modern Christianity, the Korean story will demand attention.