Yiguandao focuses on the worship of the Infinite Mother (Wujimu), also known as the Eternal Venerable Mother (Wusheng Laomu), which is also a feature of other Chinese folk religions. The source of things, It is neither male nor female, though it is called "Mother" or "Heavenly Mater". It is the primordial force of the universe, the fire, that animates all things. It is the Tao, as Yiguandao doctrines explain.^[5]

In the 16th century, the Eternal Mother began to take the place of the Holy Patriarch. A mythology surrounding the Mother began to form, integrating the beliefs about Maitreya, which had been widespread since the Yuan dynasty. The Maitreya belief is millenarian, claiming that the world would come to an end soon and Maitreya would incarnate himself in the physical plane to save humanity.^[5]

In the Mother belief, the Maitreya is one of the three enlightened beings sent by the Mother herself to bring salvation.^[5] Further myths explained the creation of the world and mankind: the Eternal Venerable Mother gave birth to yin and yang and two children, Fuxi and Nüwa, who begot auspicious stars and all sentient beings. The human beings were sent to the east and lost their memory of the Mother. The myth of Fuxi and Nüwa is found also in orthodox Chinese mythology.^[14]

The figure of the Eternal Mother derives from that of Xiwangmu, the "Queen Mother of the West", the ancient mother goddess of China, related to the mythical Kunlun, the axis mundi, and thus to the Hundun.^[14] The Infinite Mother is thought as omnipotent, and regarded by Yiguandao followers as merciful, worried by her sons and daughters who lost their true nature, and for this reason trying to bring them back to the original heaven. Through its development, the Eternal Mother belief has shown the qualities of the three goddesses Xiwangmu, Nüwa and Guanyin.^[15]

In all Yiguandao temples, there are three lamps situated on an altar. The central lamp represents the Eternal Mother, while the two sides lamps, both evenly situated at a lower level, represent Yin and Yang. Generally, in larger public temples, a statue of Maitreya is placed in the central position, accompanied by the Holy Teachers, Jigong on the right, and Yue Hui Bodhisattva on the left. In private temples, there is no required configuration. Members can choose statues of other deities, such as Guanyin and Guangong, or they can even choose to have none at all.^[15]

As Yiguandao's written material explains:^[16]

The important thing to keep in mind is that these deities ... serve as reminders for us to always keep their teachings in mind, and we honor them for the virtues they embody, such as tolerance, open-mindedness, cheerfulness and generosity (Maitreya); justice, fairness, honor, courage and loyalty (Guangong); compassion, giving, caring and nurturing (Guanyin).

The patriarchs of the faith are Zhang Tianran and Sun Suzhen. They are considered the final patriarchs of the divine revelation and are revered as divine entities.^[17]

Yiguandao conceives the cosmos as tripartite, consisting of the Heavenly World (理天 litian), the Spiritual Heaven (气天 qitian) and the Material World (象天 xiangtian). Litian is the heaven of the Eternal Mother, where there's no cycle of rebirth; qitian is the plane imbued by the gods and spirits who despite being in a higher realm than human beings, can still incarnate as matter.^[18] Xiangtian is the physical world that is composed of all visible things, with colors and shapes, including all the stars and the sky. Only litian is eternal, and qitian and xiangtian will be re-absorbed into litian.^[18]

Yiguandao involves an eschatological—soteriological belief: Grieving over the loss of her children, the Eternal Mother sent to the material world three enlightened beings over the "Three Eras". Accordingly, the human history is divided into "Three Eras": Qingyang Qi or Green Yang Era, Hongyang Qi or Red Yang Era, and Baiyang Qi or White Yang Era. Dipankara Buddha presided over salvation in the Green Yang Era, Gautama Buddha in the Red Yang Era, and Maitreya Buddha will preside over the third period of salvation, the White Yang Era, which began in 1912 and continues even now.^[19]

Extreme ruthlessness and craftiness in human behavior and disasters are associated with the end of the third period and final salvation. Cultivation of the Tao is the opportunity for repentance and purification during the White Yang Era. Those who devote their efforts to the spread of the Tao will be repaid for their merits, regardless of their societal status.^[19]

Yiguandao believes that there is something in this world called Tao. Tao is the Absolute Truth. Tao exists before Heaven and Earth. It will still exist after the destruction of Heaven and Earth. Tao is the origin of everything. Tao is embedded in everything. Tao is the essence of everything. Nowdays science and technology dominate the society, mankind become corrupted and morality has detoriated. Catastrophes strikes everywhere. In bring salvation to mankind, the Merciful God has ordained the Enlightened Teacher with Tian-Ming (天命 Mandate of Heaven) to descend and transmit Tien-Tao. Once everyone follows Tao, everyone's soul will restored to his True Self and all will be saved from the Final Catastrophe.^[20]

Since the ancient time, Tao has rarely been revealed to human. Transcending the cycle of birth and death was very difficult to achieve. In those times, one must have practiced Tao for many lives and have traveled widely to seek the Enlightened Teacher in order to receive Tao. Today, mankind is approaching the Final Judgement. To save the good, God makes Tao available to everyone. In the last period (White Yang Era), salvation is achieved by means of "offering three treasures" that enable the Yiguandao followers to transcend the circle of birth and death and directly ascend to the Heavenly World after they die.^[20]

Yiguandao developed a set of theories on "test" (考 kao). From the perspective of sectarian, one must experience various kinds of tests in the process of cultivation : no tests, no improvement. Yiguan Dao identifies several kinds of tests, such as the inner test (內考 neikao -afflictions such as illness, pain, fire, flood, and robbery), the outer test (外考 waikao - ridicule from relatives, friends, and neighbors, and oppression and violence from government officials), the test of anger (氣考 qikao), the unusual test (奇考 qikao), the test of success (順考 shunkao), the test of adversity (逆考 nikao), the test of confusion (顚倒考 diandao kao), and the test of Dao (道考  daokao).^[21]

This theory is the one they believe to cope with the persecution during surpression. One of tests is the "test from the state" (管考 guankao), which refers to "suppression and violence from government officials."^[22] According to the Yiguan Dao theory, suppression can benefit the sectarians at least from the following aspects. First, since repression is a test arranged by the Eternal Venerable Mother to select genuine believers, those who pass the exam will be rewarded after they enter the Heaven. Specially, their heavenly statuses (果位 Guowei) are based on the sufferings they experienced during the suppression. The more they suffer, the higher the heavenly status they will gain after death. Second, suppression helps "remove bad habits and refine bad temper" (去毛病 改脾氣 Qumaobing gaipiqi). The sect holds that those primordial spirits sent by the Mother were pure, but they gradually lost their true nature and became ruthless and crafty. Suppression can make people reflect on themselves and discard bad habits and temper, such as impatience and pride. Finally, bearing persecution is a way to reduce the karmas (業障 Yezhang), which are accumulated because of a person's wrong actions during the successive phases of the person's existence. Through confronting and enduring suppression, believers can gain merits (功德 gongde), which can help them get rid of the circle of birth, death, and rebirth. In short, the more the sectarians suffer, the more karma they will reduce; the more merits they accumulate by enduring distress, the higher the heavenly status they will achieve.^[23][22]

Vegetarianism is one of the core teachings of Yiguandao.^[24][25] Vegetarianism is taught from a variety of perspectives including health, ecology, environmental sustainability, reducing animal suffering and spiritual development.^[26] Yiguandao followers are said to operate 90% of Taiwan's vegetarian restaurants.^[27]

The rite of initiation involves the "offering of the Three Treasures" (传三宝), which are the "mystic portal" (玄關), "pithy formula" (口诀), "hand seal" (合同).^[28] The Three Treasures are the saving grace offered by the Eternal Mother to people who received the initiation. They enable Yiguandao members to transcend the circle of birth and death and directly ascend to Heaven after they die.^[29]

Yiguandao followers regard the initiation ceremony as the most important ritual.^[29] The full meaning of the Three Treasures is a secret of Yiguandao followers and is strictly prohibited from being spread openly to those who have not gone through the initiation process.^[30] The Three Treasures are also used in daily life as a form of meditation.^[31]

A unitary anthology of Yiguandao's writings, the Yiguandao Canon (一貫道藏 Yīguàndào zàng), was published in the 2010s with the purpose of offering a systematic overview of the religious doctrines.^[32]

Yiguandao originated in the late 19th century in Shandong as a branch of Xiantiandao (先天道; "Way of Former Heaven"), which in turn was founded in Jiangxi in the 17th century Qing dynasty as an offshoot of the Venerable Officials' teaching of fasting (老官齋教 Lǎoguān zhāijiào), a branch of the Dacheng (大乘 "Great Vehicle") or Yuandun (圓頓 "Sudden Stillness") eastern proliferation of Luoism.^[33][34] It has also been traced to the White Lotus tradition.^[11][35][36]

In the 1870s, under persecutions from the Qing, Xiantiandao fragmented into several independent groups. One branch led by the Shandong native Wang Jueyi later developed into Yiguandao.^[37] According to Yiguandao records, Wang Jueyi was designated as the 15th patriarch of Xiantiandao through a divine revelation through writing.^[37] Wang renamed his sect the "Final Salvation" (Mohou Yizhu) and deeply contributed to the development of its theology and ritual, now being regarded as the real founder of modern Yiguandao.^[37]

After a persecution started in 1883 because the Qing suspected that the sect intended to organize a rebellion, Wang was forced to live secretly until his death.^[38] Liu Qingxu succeeded the leadership becoming the 16th patriarch. In 1905, borrowing a Confucius saying that "the way that I follow is the one that unifies all" (wudao yiyiguanzhi), he gave the religion the name Yiguandao ("Unity Way").^[38]

Under Liu the Yiguandao remained small. Things changed after Lu Zhongyi became the 17th patriarch in 1919. Claiming to be the incarnation of Maitreya, Lu gathered thousands of members in Shandong. When Lu died in 1925 one group of the followers he left was led by Zhang Tianran, the man who became the 18th patriarch in following years.^[38]

Between the late years of the Qing dynasty and 1945, China went through a period of crisis, civil unrest and foreign invasion.^[39] The Confucian orthodoxy and the empire crumbled quickly. In the republican China between 1912 and 1949 folk religious sects mushroomed and expanded rapidly.^[39]

Zhang Tianran, whose secular name was Zhang Guangbi, was born in 1889 in Jining, Shandong. In 1915, he was initiated into Yiguandao by Lu Zhongyi, the 17th patriarch of the sect. After the death of Lu in 1925 the movement fragmented due to strife over the leadership. One of the subgroups that formed was led by Zhang Tianran.^[40]

In 1930, Zhang Tianran became the 18th patriarch of Yiguandao.^[38] He took Sun Suzhen as his partner, proclaiming that their marriage was a message from the Eternal Mother, and that he was the incarnation of Jigong, a deified miracle monk that lived between the late 12th and the 13th century.^[41] However, few members welcomed the new claims; many challenged the validity of the revelation and left the group. For this reason, Zhang Tianran and his wife moved to Jinan in 1931. There, different religious groups were competing with each other, and Zhang Tianran began preaching Yiguandao himself.^[40]

Zhang Tianran recruited hundreds of followers, and Jinan became the main base of Yiguandao.^[42] Many initiated members began preaching in other big cities, where Yiguandao was well received. From 1934 Yiguandao missionaries were sent to Tianjin and Qingdao. To facilitate the spread Zhang Tianran restructured Yiguandao, that since then had preserved the nine-levels structure (jiupin liantai) of Xiantiandao. The new structure had four levels, Zhang as the patriarch, and below him the leaders of the way (daozhang), the initiators (dianchuan shi), and further below the masters of the altars (tanzhu). The initiators functioned as missionaries, while the masters of altars were managers of administrative units composed of multiple congregations.^[42]

With the rapid growth of Yiguandao, Zhang Tianran's status as a divine patriarch (shizun) was strengthened, with a large number of pamphlets published to justify his divinity. The following one is an example:^[43]

When our great teacher was born, his eyes and eyebrows were perfectly shaped, and there was depth and wisdom in his eyes. [...] On his forehead, he had a third eye. His nose was straight like that of a dragon, and his head was like that of a god. His mouth was perfect and he already had a long beard. His earlobes touched his shoulders, and his arms were very long (all signs of great wisdom and ability). He walked beautifully and perfectly, with long strides, and was obviously not of the mortal world. On his left hand, he had a red birthmark shaped like the sun and on his right one like the moon; they were so red that they would leave a mark when he touched his hand to paper. On his left foot, he had the seven stars of the Big Dipper, and on his right foot, the six stars of the Southern Dipper. Because of this, although he had been born into the mortal world, everyone knew that he was one with the Universe—the living enlightened Jigong, who was sent by heaven to save humanity.

With its centralized authority and highly degree of organization, Yiguandao had an extraordinary power of mobilization. At first, fuji, the practice of receiving direct revelations from the gods which is closely linked to the Chinese intellectual tradition since the Song dynasty, contributed to the dynamism of the movement.^[44]

Divine revelations were published in "morality books" (shanshu), and distributed to the general public for moral edification of the society. Divine writing was also used to offer oracles for everyday problems.^[45]

Fuji was introduced into Yiguandao despite Wang Jueyi, the 15th patriarch of the lineage, discouraging it. Zhang Tianran distinguished between "innate writing" (xiantian ji), received by juvenile media and considered superior to "acquired writing" (houtian ji), received by old media. Youth purity is considered more conductive of divine revelation. Zhang stressed that only Yiguandao fuji is xiantian ji (revealing the original Heaven).^[45]

Divinely inspired writing was later rejected by some branches of Yiguandao, as new scriptures produced new schisms, and gradually declined within the religion as a whole.^[46]

Yiguandao also spread and gathered financial support through the performance of "rituals of salvation of the ancestors".^[45] Rules and practices for the followers were also systematized.^[47] Zhang Tianran also gave much importance to aggressive missionary work, contrasting with the Chinese tradition of peaceful coexistence. In 1938 he held missionary workshops named "stove meetings" (lu hui) to train missionaries in Tianjin. Hundreds of missionaries were trained in these workshops, and they were sent all over the country. Many became influential leaders of Yiguandao.^[48]

Through missionary activity, in the political and social turmoil caused by the Japanese invasion of China in the 1940s, that made Yiguandao's millenarian beliefs more convincing to the masses, the religion grew rapidly, reaching an estimated membership of 12 million.^[1] Even a number of top officials of the Japanese puppet government of Wang Jingwei converted to Yiguandao.^[49]

With the rise of the Chinese Communist Party in 1949, Yiguandao was suppressed, being viewed as the biggest reactionary huidaomen. In December 1950, The People's Daily published the editorial "Firmly Banning Yiguandao" (Jianjue Qudi Yiguandao), proclaiming that the movement had been used as a counterrevolutionary tool by imperialists and the Kuomintang. The article claimed that Yiguandao members were traitors collaborating with the Japanese invaders, Kuomintang spies, and reactionary landlords.^[50]

The editorial marked the beginning of the nationwide campaign of eradication of Yiguandao. The main target of the campaign was to destroy the movement's organization and leadership. The top leaders were executed or sent to prison, the members were forced to undergo political re-education and they were kept under close surveillance.^[51]

An exhibition denouncing Yiguandao was held in Beijing in January 1951. In 1952, the communists released "The Way of Persistently Harming People" (Yiguan Hairen Dao), a film against Yiguandao. A number of Yiguandao believers, including Sun Suzhen, fled to Hong Kong and later to Taiwan, where the religion currently thrives.^[52]