Cao Dai is a highly syncretic monotheistic religion that seeks to establish a basis upon which major world religions can be united. History is divided into three periods of revelation. The first period was around 2500 BCE, a time when God inspired the establishment of Judaism, Hinduism and early Chinese religion. The second period coincided with the emergence of Buddhism, Christianity and Islam. These divinely inspired religions became corrupted because they came to be associated with their founders rather than recognised as truly universal religions. The third (present) period is one in which divine revelation occurs through inspired mediums. The message of Cao Dai is that all religions are in fact one even though they have different names.
Cao Dai venerates a host of different figures including Victor Hugo, Sun Yat Sen, and Trangh Trinh, a 16th century Vietnamese poet and philosopher. Its ethics are based in the belief in the reincarnation of the soul. Members of the sect are required to pray at least once a day, avoid violence to sentient creatures, to be honest, to avoid adultery, to be sober, and not to use bad language. Adhering to these rules will lead either to a beneficial rebirth or, ultimately, escape from the cycle of birth and death and rebirth in heaven. Failure to do so will lead to rebirth on another planet where life is harsher than on earth.
Cao Dai has its own hierarchy based on the Roman Catholic Church. Pope, bishops, cardinals and archbishops. Women are allowed to officiate at services.

Cao Dai was founded by Ngo Van Chieu, an administrator working for the French in southern Viet Nam. In 1925 Ngo Van Chieu underwent a spiritual experience in which he believed himself to have encountered the divine being (Cao Dai). In 1926 an ecclesiastical hierarchy was established with Le Van Trung appointed as Giao tong (pope). During the following decade the movement the movement grew rapidly but also split into a number of subgroups.
Cao Dai has been staunchly anti-communist and worked for the establishment of a Viet Nam free from the influence of the capitalist west and communist east. The unification of Viet Nam by the Viet Cong in 1975 and the establishment of a communist-based government imepeded the work and growth of the sect. Cao Dai has, however, established itself outside of Viet Nam - in Australia, the United States, the United Kingdom, France and Germany. The more recent liberalisation of Viet Nam has provided scope for renewed religious activity in that country..