section_path: Demographics/Religion
section_name: Religion
paragraph_text: Religion
  
  Religion in South Korea (2015 census)
  
  According to the results of the census of 2015, more than half of the South Korean population (56.1%) declared themselves not affiliated with any religious organizations. In a 2012 survey, 52% declared themselves "religious", 31% said they were "not religious" and 15% identified themselves as "convinced atheists ". Of the people who are affiliated with a religious organization, most are Christians and Buddhists. According to the 2015 census, 27.6% of the population were Christians (19.7% identified themselves as Protestants, 7.9% as Roman Catholics) and 15.5% were Buddhists. Other religions include Islam (130,000 Muslims, mostly migrant workers from Pakistan and Bangladesh but including some 35,000 Korean Muslims), the homegrown sect of Won Buddhism, and a variety of indigenous religions, including Cheondoism (a Confucianizing religion), Jeungsanism, Daejongism, Daesun Jinrihoe, and others. Freedom of religion is guaranteed by the constitution, and there is no state religion. Overall, between the 2005 and 2015 censuses, there has been a slight decline of Christianity (down from 29% to 27.6%), a sharp decline of Buddhism (down from 22.8% to 15.5%), and a rise of the unaffiliated population (from 47.2% to 56.9%).
  
  Christianity is South Korea's largest organized religion, accounting for more than half of all South Korean adherents of religious organizations. There are approximately 13.5 million Christians in South Korea today; about two thirds of them belonging to Protestant churches, and the rest to the Catholic Church. The number of Protestants had been stagnant throughout the 1990s and the 2000s but increased to a peak level throughout the 2010s. Roman Catholics increased significantly between the 1980s and the 2000s but declined throughout the 2010s. Christianity, unlike in other East Asian countries, found fertile ground in Korea in the 18th century, and by the end of the 18th century it persuaded a large part of the population, as the declining monarchy supported it and opened the country to widespread proselytism as part of a project of Westernization. The weakness of Korean Sindo, which—unlike Japanese Shinto and China's religious system —never developed into a national religion of high status, combined with the impoverished state of Korean Buddhism, (after 500 years of suppression at the hands of the Joseon state, by the 20th century it was virtually extinct) left a free hand to Christian churches. Christianity's similarity to native religious narratives has been studied as another factor that contributed to its success in the peninsula. The Japanese colonization of the first half of the 20th century further strengthened the identification of Christianity with Korean nationalism, as the Japanese coopted native Korean Sindo into the Nipponic Imperial Shinto that they tried to establish in the peninsula. Widespread Christianization of the Koreans took place during State Shinto, after its abolition, and then in the independent South Korea as the newly established military government supported Christianity and tried to utterly oust native Sindo.
  
  Among Christian denominations, Presbyterianism is the largest. About nine million people belong to one of the hundred different Presbyterian churches; the biggest ones are the HapDong Presbyterian Church, TongHap Presbyterian Church and the Koshin Presbyterian Church. South Korea is also the second-largest missionary-sending nation, after the United States.
  
  Buddhism was introduced to Korea in the 4th century. It soon became a dominant religion in the southeastern kingdom of Silla, the region that hitherto hosts the strongest concentration of Buddhists in South Korea. In the other states of the Three Kingdoms Period, Goguryeo and Baekje, it was made the state religion respectively in 372 and 528. It remained the state religion in Later Silla and Goryeo. It was later suppressed throughout much of the subsequent history under the unified kingdom of Joseon, which officially adopted a strict Korean Confucianism. Today, South Korea has about 7 million Buddhists, most of them affiliated to the Jogye Order. Most of the National Treasures of South Korea are Buddhist artifacts.