Jeungsanism, as his movement was called, and various Korean new religions (sinheung jonggyo, literally, "newly emerged religions") derived from it, have been seen by scholars as a syncretism of Buddhism (Bul-gyo), Confucianism (Yu-gyo), Taoism (Do-gyo) with unique religious insights of Kang and certain elements borrowed from Christianity (Gidok-gyo), as well as an underlying Korean shamanism (Musok-Sinang).

For instance, hagiographical accounts record that "at the time of his birth (...) two female fairies (仙女) descended from heaven into the delivery room," filling it with a "sweet-smelling aroma.

"[8] Later, it is claimed that he "learned Chinese classics at a Seodang and mastered them to the point of memorizing and reciting all of them by heart," through a complete understanding of their meaning.

[11] Reputedly, he also visited Kim Il Bu (金一夫; 1826–1898), the well known scholar who introduced the Jeong-yeok (正易), i.e. a new interpretation of the Chinese I Ching (Book of Changes).

[12] Kim is said to have offered a new arrangement of the I Ching Chinese trigrams, together with other diagrams and an explanatory text, including insights he had received in a mysterious vision.

[13] In 1860 Choe Je-u, concerned about the growing influence of the West, the increasing Japanese presence in Joseon Korea, widespread corruption in government and established religion, and abuse of power by the yangban (aristocratic social class), alleged he had a revelation from the Supreme God Sangje (Shang-ti in Chinese) and attained enlightenment.

Choe Je-u became the founder of the Donghak (Eastern Learning) movement, the prototype of many subsequent Korean syncretistic new religions.

[14] Gang Il-sun, in fact, insisted that he was Sangje himself who, prior to incarnating on earth, had bestowed that revelation upon Choe Je-u.

[21] Daesun Jinrihoe believes that there was a residual work of reordering, to be completed by his successors in the religious orthodoxy, Jo Jeongsan (趙鼎山; 1895–1958) and Park Wudang (朴牛堂; 1918–1996).

Cha's branch, known as Bocheonism (Bocheob-gyo), according to some scholars "had more followers during the Japanese colonial period than any other religion, more than an estimated 6 million adherents.