From the beginning, missionary work in Korea has emphasized church planting and leadership training. The "three indigenous principles of missions" (self-support, self-propagation, and self-government) that are commonly used in modern mission strategy have been faithfully applied in the Korean church, resulting in rapid church growth. Today, more than 15 million Koreans are Christians, nearly 31 percent of the total population of South Korea.
The Reformed Church in America partners with the Presbyterian Church of Korea (PCK), which claims 2.3 million members throughout the country. In response to a request from the PCK, the RCA provides funds to support mission work among the large population of migrant workers in South Korea. The partnership of three churches--the Reformed Church in America, the Presbyterian Church of Korea, and the United Church of Christ in the Philippines--has resulted in shared ministry with and for foreign workers in South Korea as a social response to the gospel's mandate to serve those who are in need. South Korea has more than 350,000 migrant workers who live and work in difficult and dangerous conditions. The Mission Society for Migrant Workers, a ministry of the Presbyterian Church of Korea, reaches out to this marginalized sector of the population by providing a wide variety of social services through Shalom House, a shelter for unemployed migrant workers. Shalom House offers migrant workers legal advice and assistance with the challenges of overcoming the language barrier and finding shelter.