Throughout the ages, there have been various popular religious traditions practiced on the Korean peninsula. The oldest indigenous religion of Korea is the Korean folk religion (a version of Shamanism), which has been passed down from prehistory to the present. Buddhism was introduced to Korea from China during the Three Kingdoms era in the fourth century, and the religion pervaded the culture until the Joseon Dynasty when Confucianism was established as the state philosophy. During the Late Joseon Dynasty, in the 19th century, Christianity began to gain a foothold in Korea. While both Christianity and Buddhism would play important roles in the resistance to the Japanese occupation of Korea in the first half of the 20th century, only about 4% of Koreans were members of a religious organization in 1940. Since the division of Korea into two sovereign states in 1945—North Korea and South Korea—religious life in the two countries have diverged, shaped by different political structures. Religion in South Korea has been characterized by a rise of Christianity and a revival of Buddhism, though the majority of South Koreans have no religious affiliation or follow folk religions. Religion in North Korea is characterized by state atheism in which freedom of religion is nonexistent. Juche ideology, which promotes the North Korean cult of personality, is regarded by experts as a kind of national religion. Demographics in South Korea History Ancient times Before the formation of ancient tribal states, natural objects and deities were worshipped by indigenous peoples like any other. Trees(樹木) become sallow trees(沙羅樹) for giving birth to children. Bears and tigers turn into human beings, passing on the wisdom of Han Yu and protecting against disasters. Garlic, artemisia argyi, calamus, etc. are auspicious herbs or cinnabar that have the main force to revive life or exorcise evil spirits. On the other hand, there were animisms such as invisible mountain spirits and water spirits. In addition, the sun, moon, and stars(日月星辰) of Han Wei were also deified. In other words, there was a worship of nature and a worship of animism. In the former, objects and heavenly bodies of the earth and Hanul are objects of faith, but the foundation of that belief is the concept of reproduction. Hwanung as the Heavenly King had to marry the bear tribe of the earth, from which Dangun was born, and again from Dangun, Buru(부루; 夫婁) came out, and Buru had a totem