Today in 1884 we remember how Dr. Horace Newton Allen arrived in Chemulpo, Korea, praying for an opportunity to evangelize Korea, where the introduction of Christianity was illegal. A rebellion in Seoul led to the prince, a nephew of the king, suffering seven sword thrusts. Refusing to flee with other westerners, Allen tended the prince, who recovered. Recognizing that western medicine is an outgrowth of Christianity, the grateful king removes restrictions on Christianity. This would start a third wave of the spread of Christianity on the Island
Catholicism had been introduced 200 years before by Confucian scholars who had encountered it in China. In 1603, Yi Gwang-jeong, a Korean diplomat, had returned from Beijing carrying several theological books written by Matteo Ricci, an Italian Jesuit missionary to China (pod of July 17 ) Therefore Catholicism in Korea began as an indigenous lay movement rather than being imposed by a foreign missionaries and indigenous lay-workers rather than foreign prelates carried Catholicism to many. Since Christianity began as largely a grassroots effort in Korea, it spread more quickly through the population. After a period growth of Christianity, through the dissemination of Ricci’s writings, particularly ‘The True meaning of the Lord of Heaven’ , This had argued that Confucianism and Christianity were not opposed and in fact are remarkably similar in key respects. Popular at a grassroots level this provoked academic controversy in Korea as it overturned Confucian veneration of elders and tradition. Members of the Silhak "practical learning" school believed in social structure based on merit rather than birth and were attracted to what they saw as the egalitarian values of Catholicism.
Ricci’s books were written in the form of a dialogue, originally in Chinese and had also been very popular in China provoking the ire of other missionaries and lead to the Chinese Rites controversy, where some missionaries raised the question whether Ricci and other Jesuits had gone too far and changed Christian beliefs to win converts. As well as Korea it also spread to Vietnam, and a catechism for Vietnamese and Korean Christians were written from it. However, In 1758, King Yeongjo of Joseon outlawed Catholicism as an "evil practice." But the official line softened thirty years later and French and Chinese Catholic priests were invited by the Korean Christians. 100 years later, its popularity led the King to see it as a subversive influence and in the Catholic Persecution of 1866, 8,000 Catholics across the country were killed, including nine French missionary priests. The gradual opening of Korea to the outside world brought religious toleration for the remaining Catholics and also introduced Protestantism via American missionaries, beginning in 1884. The first Protestant missionary to enter Korea was Horace Newton Allen, a Presbyterian missionary who became an American diplomat. He served in Korea until 1905, by which time he had been joined by many others.
Christianity, seem to have had a special appeal to Koreans in the North and there were early migrations to the northern provinces, creating a society of mixed backgrounds without an aristocracy and without long-standing religious institutions. During Japanese colonial rule from 1910 to 1945, the North became the more industrial region of Korea. The area was highly receptive to Catholic and Protestant missionaries in the late nineteenth century, who brought Western knowledge, and established hospitals and Western-style medical care, schools, and a window to the wider world. In a reversal of previous Southern dominance, the North produced many influential figures in Korean history. After 1945, North Korea's Soviet-influenced state policy of atheism caused most Christians to flee to South Korea in pursuit of religious freedom. Communist North Korea cut itself off from most of the world becoming the Hermit Kingdom. In South Korea, the influence on education has been decisive, as Christian missionaries started 293 schools and 40 universities including three of the top five academic institutions.
Christianity was associated with more widespread education and Western modernization. Catholicism and Protestantism are seen as the religion of the middle class, youth, intellectuals, and urbanites, and has been central to South Korea's pursuit of modernity and westernization after the end of World War II and the liberation of Korea. In the early 21st century, however, the growth of Protestantism has slowed, perhaps due to scandals involving church leadership, fundamentalism and conflict among various sects. Some analysts also attribute this to overly zealous missionary work. By 2010, 29% of the South Korean population is Christian and the government put the number of Protestant churches at 17,000 and Catholic churches at 3,000. Now South Korea provides the world's second-largest number of Christian missionaries, surpassed only by the United States.
Pope Francis accepted an invitation to visit South Korea in August 2014. The four-day visit included a mass where the Pope beatified 124 Korean Catholic martyrs. An invitation for North Korea's Catholics to attend was declined, due to South Korea's refusal to withdraw from military exercises which it had planned with the United States