In its young history of just over 200 years, Christianity has become a vibrant and prominent part of society in Korea. The Roman Catholic Church marks 1784 as the start of its history with the arrival of Yi Seung-Hoon, a young Korean man who had been baptized by a Jesuit priest in China. Despite harsh persecution against Roman Catholicism that led to martyrdom, Christianity continued to spread as the early Christians passionately evangelized their families, friends, and neighbors. Although Protestant Christianity would not begin its official history in Korea until one hundred years later with the arrival of an American medical missionary in 1884, there already was a thriving Protestant mission in Manchuria where missionaries were becoming increasingly interested in Korea. Koreans baptized by Protestant missionaries in Manchuria returned home to evangelize.

In the early days of the church, Christians led an itinerant life, preaching about Jesus and his ministry, and distributing copies of the new translation of the New Testament. The early Christians, together with missionaries, translated the New Testament into the Korean language, built schools for indigent boys and girls, orphanages, hospitals and clinics. By working with disadvantaged and marginalized members of society, Christians developed a reputation for having egalitarian and democratic ideals as well as a strong social conscience. Additionally, Christianity was not seen as a religion of the oppressor or as an imperialist religion, because the Japanese practiced Shintoism.

Japan officially annexed Korea in 1910. As the Independence Movement grew with many of its leaders Christian, the church continued to support the movement in the face of great opposition by the Japanese provisional government. At the same time as the church began to face great external pressure from the Japanese, it was experiencing internal dissent over its role in the Independence Movement. In a parallel situation, the missionary community was also divided over its involvement in and support of the Independence Movement. Eventually, the faction that opposed any overt support for the Independence Movement was successful, resulting in a depoliticization of the church. Many Korean Christians, however, continued to actively support the Independence Movement.

After the end of the Great Pacific War, Korea suffered an involuntary partition into North and South Korea which led to a devastating two-and-a-half-year war that claimed an estimated 3 million civilian casualties.

Since the 1960s, South Korea has been on a course of rapid economic development towards its goal of becoming an industrialized nation. During this period of rapid economic development and military dictatorship government, the church appeared to be heading in two different directions. Most church denominations mainly focused on local church growth and were uncritical of the military dictatorship government. Other churches struggled for human rights, democratization, and reunification of the divided peninsula even at the risk of surveillance, imprisonment, and torture. Those Protestant churches that were critical of the government worked through the National Council of Churches in Korea. The Catholic Church was also supportive of Catholics who worked for human rights and democratization.

The church has experienced great growth in church membership, especially since the beginning of the 1970s. Currently, 25% of the general population are Christian. As Christianity in South Korea enters the 21st century, the landscape has changed. Fewer missionaries are coming to Korea, while many Korean missionaries are sent abroad. The church in Korea is involved in a wide range of outreach mission work, including urban industrial and rural mission, and ministry with undocumented migrant workers, sex workers, victims of domestic and sexual violence, orphans, the elderly, the unemployed and homeless, and ethnic Koreans living in other countries The church faces important questions about its role in society and culture as South Korea heads into the 21st century still a divided country.