The Religions of South Vietnam in Faith and Fact, US Navy, Bureau of Naval Personnel, Chaplains Division [1967], at sacred-texts.com
Marriage
Marriage and death are perhaps the most sacred and solemn events among most of the Vietnamese people, either lowlander or mountaineer. To the lowland or ethnic Vietnamese, marriage is an affair of greater interest and concern to the entire family than to the man and woman to be married. It is arranged by the family with much care because to them the essential purpose is the procreation of male offspring to perpetuate the family and to assure a continuing ancestral worship.
The continuing cult of ancestral worship is one of the reasons that few families want a mixture of racial blood lines: it is feared that proper worship will not be maintained if such occurs. Marriages are arranged after social factors, horoscope readings, etc., have been studied and found acceptable. The ceremonial procedure of the marriage rite is in three parts; (a) official request for engagement, (b) the engagement, and (e) the marriage itself.
Among the non-Christian Vietnamese of the lowlands, the marriage ceremony seems to consist of ceremonial presentations of the bridegroom to the forebearers--living and dead--and family of the bride, with this taking place in front of the family ancestral altar; and the bride likewise presenting herself before the ancestral altar of the grooms family and pledging to henceforth give allegiance to them.
This is followed by feasting and celebrations as marriage is an important step in assuring the living family that veneration of themselves as ancestors after death will be continued.
While there seems to be some change of marriage customs in the cities due to colonialization and the movies, the traditional customs are very evident. A number of charming young ladies in their early twenties affirmed that their future husbands would be chosen by their mothers; avoiding making mother unhappy was more important than their own choice of mates, as violation of the customs would create much sadness.
Among Christians, a distinctly Christian ceremony is utilized, but cultural patterns not in conflict with Christian doctrines are firmly adhered to among the better classes of society.