Vietnam is officially an atheist country, as declared by the country's communist regime. Although in theory the country enjoys freedom of religion, in practice there are a number of limitations on worship. For instance, only eight, state-sanctioned religions are officially permitted, and no religion may propagate an ideology that is considered to contradict that of the government.
Despite this, Vietnam has a number of major religions, each with a large number of followers - the most significant of which is Mahayana Buddhism, which claims a 16.4% share of the population according to the Pew Research Centre in Washington DC, who conducted a survey into religion in Southeast in 2010. Other religions with a significant following include Catholicism, Protestantism, Theravada Buddhism, Islam, Hoa Hao, and Cao Dai.
According to the national census, about 81% of Vietnamese consider themselves non-religious, however this figure does not take into account the many Vietnamese who continue to practise "informal" religious customs and folk religions, most of which not recognised by the government. Pew Research Centre figures suggest that the number of Vietnamese who fall into this category may be around 45.3% of the population.
Triple religion (tam giao)
The phrase "three teachings" refers to the combination of Confucianism, Taoism and Buddhism found in Chinese philosophy. In Vietnam, the three teachings have become entwined with each other, as well as with indigenous Vietnamese beliefs, to create a syncretic religion that is followed to some extent by most Vietnamese. Though the idea of following more than one set of beliefs at once may seem paradoxical, for most Vietnamese (and, as you'll find throughout this article, most Cambodians and Lao) there is no inherent contradiction in making an offering to Buddha, a national saint and a personal ancestor depending on the occasion.
Thus, although Vietnam is generally thought of as Buddhist, and as many as 85% of Vietnamese regularly visit Buddhist pagodas, it is actually more accurate to see most Vietnamese as practitioners of a synthesis of disparate Asian religious traditions. This system of beliefs is known as tam giao: triple religion.
There is some debate as to whether Buddhism first arrived in Vietnam by way of India in the third to second centuries BC, or by way of China in the first to second centuries AD. What we do know is that by the end of the second century, Vietnam had developed into a major Mahayana Buddhist centre, with most of its influence over the next 18 centuries to come from Chinese Buddhism. Meanwhile, Theravada Buddhism (more closely related to the Indian tradition) would become established in the southern portion of the country - which until the 17th century was Khmer territory rather than Vietnamese.
From 1954 until 1975, when Vietnam was split into north and south, President Ngo Dình Diem (a member of the Catholic Vietnamese minority) began introducing certain policies that both favoured Catholics and antagonised the 50-70% Buddhist majority. Buddhist freedom of worship began to be restricted, triggering mass protests against the government in what is now termed the "Buddhist crisis". The crisis culminated in the monk Thich Quang Duc's famous self-immolation on the streets of Saigon in 1963; an event that was quickly followed by the withdrawal of US support for President Diem's regime, then Diem's deposition and death.
Following the Buddhist crisis, Vietnamese Buddhism enjoyed a growth in political strength throughout the 1960s and the Unified Buddhist Church of Vietnam was formed. After the fall of Saigon in 1975, however, the new communist state placed further restrictions on Buddhist practices (along with those of many other religions), many of which remain in place today.
Today, Buddhism remains the most popular religion in Vietnam, and is generally practised in syncretic fashion - incorporating elements from various traditions within Buddhism as well as philosophy from other faiths such as Confucianism and Taoism. Mahayana Buddhism remains the dominant sect, followed by Theravada Buddhism, then Hoa Hao.
Hoa Hao is a religious tradition based on Buddhism that was founded in 1939 by a man named Huynh Phu So from the Mekong Delta region of southern Vietnam. The faith puts emphasis on the practice of religion by laypeople and claims a large number of followers in the south of the country.
Catholicism is by far the most widespread Christian church in Vietnam, and was introduced to the country by Portuguese Catholic missionaries in the 16th century. This influence was bolstered during French colonial rule, and by later Jesuit missionaries in the following centuries. The Catholic church gained a further foothold in the 18th century when the missionary Pigneay de Behaine become a close friend and advisor to Emperor Gia Long, garnering favour for the church and ensuring that its activities were allowed to continue unimpeded.
The Protestant faith, by contrast, was not introduced to Vietnam until 1911 - when it was brought to the country by the Canadian missionary Robert A. Jaffray. Today, the combined assemblies of Vietnam's various Protestant groups are estimated to number around 70,000, in contrast to around 5.5 million for the Catholic church.
The Cao Dai religion was established in southern Vietnam in 1926, and is a monotheistic religion that credits God - rather than any prophet or Buddha - as its founder. There are a significant number of Cao Dai adherents in Vietnam, and their typical practices include prayer, veneration of ancestors, nonviolence and vegetarianism. Practitioners of Cao Dai believe that we have now entered an era in which God and mankind will be united in ways not yet imagined, and that all religions will one day be united for the salvation of all living things.