Catholicism: history, teachings, the seven sacraments and four hundred years in Vietnam

IFive sentences to start

One, Catholicism is a branch of Christianity in communion with the Pope in Rome. It professes one God in three Persons and holds that Jesus Christ is the Second Person made man. Two, the religion began with a group of Jewish disciples in first-century Judea, spread across the Roman Empire, and became a global organisation with a hierarchy running from the Pope down to the smallest sub-parish. Three, religious life revolves around the seven sacraments, with the Mass and the Eucharist at the centre. Four, Catholicism reached Vietnam in the sixteenth century and today has twenty-seven dioceses and about seven and a half million faithful. Five, it is the second largest organised religion in Vietnam after Buddhism, and the largest religious community in the world by number of adherents.

This page is written in a descriptive voice. The library reports what Catholicism professes, reports what historians can verify, and keeps the two apart. The library does not judge which religion is right and which is wrong.

IIThe Roman Empire in the first century

To understand Catholicism, one has to begin with a small strip of land on the eastern shore of the Mediterranean. Judea and the region of Galilee had been under Roman control since 63 BC. The Romans left the local people their temple, their law and their priesthood, but kept the army, taxation and the power to pass a death sentence. The governor best remembered in Christian memory is Pontius Pilate, who ruled from about the year 26 to 36.

Judaism at that time was not a single uniform block, and this is where modern readers often picture things wrongly. What the groups shared was the expectation of a Messiah, a word whose root meaning is "the anointed one". But each group imagined that figure differently: some awaited a king leading an army, some a priest who would purify the temple, some an event that would end the age.

One more detail: the empire of that day had good roads and a shared common Greek spoken across it, as well as Jewish communities in the major cities. That explains how a movement born in the villages of Galilee could reach Rome in less than thirty years.

IIIJesus Christ

Everything in Catholicism comes back to one figure. But there are two quite different ways of speaking about that figure, and mixing the two together is the source of most fruitless arguments.

On the side of history, the great majority of scholars accept that there was a historical figure named Jesus of Nazareth who lived in Galilee and Judea in the early first century. The Encyclopaedia Britannica places his birth at around 6 to 4 BC and his death at around the year 30, and treats several things as nearly certain: he was baptised by John the Baptist, he preached the Kingdom of God, he clashed with the religious authorities of his day, and he was crucified under Pontius Pilate. As for the miracles and the resurrection, the same source classes them as the testimony of believers.

Beyond the Christian texts there are a few ancient sources from outside the faith. The Roman historian Tacitus, in book 15, chapter 44 of his Annals, written around the year 116, says that the man from whom the Christians took their name was executed by Pontius Pilate. The Jewish historian Josephus has a short passage mentioning James, the brother of Jesus who was called Christ, and a longer passage known as the Testimonium Flavianum, which almost all scholars agree was later expanded. The degree of certainty falls into three levels. Almost no one disputes that a man named Jesus was crucified in Jerusalem. Still debated are the content of his teaching and the chronology. Outside the reach of history altogether are the miracles and the resurrection.

IVTwo thousand years on a timeline

Four kinds of event recur across those two thousand years. First, the ecumenical councils, meetings of all the bishops to define doctrine, twenty-one of them to date. Second, the persecutions, followed by the moment the religion was recognised. Third, the two great schisms, in 1054 and 1517. Fourth, the waves of internal reform. A few of the earliest dates are only conventional.

• around 30The first disciples
  After the death of Jesus, his disciples gathered in Jerusalem and began to preach, at that time still living within Judaism.
• around 64 to 67The persecution under Nero
  The emperor Nero blamed the Christians for the burning of Rome. Tradition places the deaths of the Apostles Peter and Paul in Rome in this period. The bishop of Rome was later counted as Peter's successor.
• 2nd to 3rd centuryPersecutions spread
  Several waves of persecution under the emperors Decius and Diocletian, the heaviest in the early fourth century. In this same period the list of books accepted as Scripture took shape.
• 313The Edict of Milan
  Constantine and Licinius granted religious freedom. Christianity went from banned to legal, and by the end of the fourth century it was the state religion of Rome.
• 325The Council of Nicaea
  The first ecumenical council. It condemned the teaching of Arius that the Son was a created being, and defined the Son as of one substance with the Father. The creed recited at Mass today comes from this council and from the Council of Constantinople in 381.
• 431 and 451Ephesus and Chalcedon
  Ephesus proclaimed Mary the Mother of God. Chalcedon defined that in Jesus there are two natures in one Person.
• 1054The East-West Schism
  The legates of Pope Leo IX and Patriarch Michael Cerularius excommunicated each other, marking the split between Roman Catholicism and Eastern Orthodoxy.
• 1517The Protestant Reformation
  Martin Luther published his theses against the sale of indulgences. Western Christianity divided into Catholicism and the Protestant denominations.
• 1545 to 1563The Council of Trent
  Held in three sessions in response to the Reformation: it restated the doctrine of the sacraments and of salvation, fixed the biblical canon at seventy-three books, and established seminaries for training priests.
• 1869 to 1870The First Vatican Council
  Proclaimed the dogma of papal infallibility, which applies only when the Pope solemnly defines a matter of faith or morals for the whole Church.
• 1929The Lateran Treaty
  The Holy See and Italy signed a treaty creating Vatican City State, the smallest independent state in the world.
• 1962 to 1965The Second Vatican Council
  Convened by Pope John XXIII and closed by Pope Paul VI, with about two thousand four hundred council fathers and sixteen documents. The event that shaped modern Catholicism: local languages in the liturgy, the role of the laity, interreligious dialogue.

VCore teachings

Catholicism has a summary of its faith recited together every Sunday, called the Creed, and a full presentation in the Catechism of the Catholic Church. Unlike many East Asian traditions, this religion has a written list of beliefs that is regarded as binding.

The Holy Trinity

Catholicism professes one single God, but that God exists in three Persons: the Father, the Son and the Holy Spirit, distinct from one another yet of one nature, one power and one eternity. Not three gods, and not one god wearing three faces at different moments. The tradition calls this a mystery, something beyond the reach of reasoning. Vietnamese readers often compare it with the triads worshipped in temples and palaces of folk religion, but the comparison misleads, because the folk triads are three separate beings.

Creation and original sin

The tradition holds that God created heaven and earth out of nothing, out of goodness and not out of any need. Human beings are created in the image of God, which means they have reason, freedom and the capacity to love, and therefore a dignity that no one may violate. Original sin is often misunderstood as a sin passed from parent to child like a hereditary disease. The catechism does not say that. Original sin refers to the state of rupture between humanity and God, and every person is born inheriting that state, not inheriting anyone's personal guilt.

The Incarnation

Incarnation literally means taking on flesh. The tradition holds that the Second Person truly became a man, born of the Virgin Mary, and lived a human life with a family, a trade, hunger, thirst and tears. He was not God in human disguise, nor a man raised to the rank of a god. The consequences reach far: the body is not regarded as something evil to be rejected, and because God became visible, the Church permits painted images and carved statues.

Redemption

The tradition holds that the death of Jesus on the cross and his resurrection are the sacrifice that reconciles humanity with God. The word redemption borrows the image of buying a slave back, but the catechism stresses that this was not a price paid to the devil, nor an angry God who needed blood before he could be appeased. The official presentation places the emphasis on self-giving love, with God himself taking the first step.

Salvation and grace

Grace is the life of God given to human beings freely, not earned by merit. Catholicism teaches that people are saved by grace, and that grace calls for a response in faith and in the way one lives, which means that works also have their part. This is the historic point of difference with the Protestant denominations, which stress the formula of faith alone. About the life to come, the tradition holds that there is judgement, heaven, hell and purgatory.

Faith, hope and charity

The life of the believer is arranged around three virtues the catechism calls theological. Faith is accepting as true what God has revealed. Hope is living in reliance on his promises. Charity is loving God above all things and one's neighbour as oneself. Saint Paul placed charity highest, because faith and hope will end once one sees face to face, while charity endures forever.

The Creed

All of the above is recited compactly in the Creed, of which two versions are in common use, the Apostles' Creed and the Nicene-Constantinopolitan Creed, the latter formed at the two councils of 325 and 381. The longer version follows the order of the Trinity: belief in the Father as creator, belief in Jesus Christ together with the events of his incarnation, death and resurrection, then belief in the Holy Spirit, in the Church and in the life of the world to come.

VIThe seven sacraments

A sacrament is a visible sign that Catholicism believes conveys grace effectively: a gesture that can be seen and touched, carrying a reality that cannot be seen. Water poured on the head, oil on the forehead, bread and wine on the altar, the consent spoken by a bride and groom. The catechism, following Saint Thomas Aquinas, sets the seven sacraments alongside the stages of a human life.

Among the seven, the Eucharist holds the central place, and the catechism states plainly that the other six are ordered towards it: the other sacraments give the grace of Christ, while the Eucharist contains Christ himself. That is why every church has a small cabinet in the sanctuary called the tabernacle, where the consecrated hosts are kept, and why people genuflect towards the tabernacle when they enter. Receiving Communion is also strictly regulated: one must be free of serious sin, fast for one hour beforehand, and non-Catholics do not receive, not out of discrimination but because receiving Communion is regarded as a full profession of what one believes.

VIIStructure of the Church

Catholicism has one of the most tightly organised structures of any religion in the world, quite unlike the East Asian traditions, which are organised by monastic lineage or by village. From a small sub-parish in the Red River Delta up to Rome there is a clear chain: who answers to whom, and who is responsible for what.

Territorially, the basic unit is the diocese, governed by a bishop. Several dioceses form an ecclesiastical province, and within a diocese the parishes are grouped into deaneries. The unit the faithful are closest to is the parish, with its parish priest, its church and its pastoral council. Below the parish there is the sub-parish, sometimes no more than a Catholic hamlet with a small chapel.

At the top are two entities that outsiders often confuse. The Holy See is the central governing body of the Church, made up of the Pope and the departments of the Roman Curia, and it is the entity that holds diplomatic relations with states. Vatican City State is a territory, created by the Lateran Treaty of 1929. In short: the Holy See is the authority, the Vatican is the piece of land.

VIIIThe Bible

The Bible in Catholicism is not a single book but a collection of many works written over roughly a thousand years in three languages, Hebrew, Aramaic and Greek. The Catholic canon, the official list of accepted books, contains seventy-three books, definitively settled by the Council of Trent in the sixteenth century.

A frequent question is why the Catholic Bible has seventy-three books while the Bibles of the Protestant denominations have only sixty-six. The New Testament is exactly the same on both sides. The difference lies in the Old Testament, forty-six against thirty-nine. The Greek-speaking Jewish community of Alexandria used the translation known as the Seventy, or the Septuagint, which contained books that the later Jewish canon did not accept, and the earliest Christian communities adopted it, while the Jewish tradition in Palestine later settled on thirty-nine books in Hebrew. The figure of forty-six Old Testament books is the Catholic canon, fixed by the Council of Trent in 1546. In the sixteenth century Martin Luther followed the Hebrew list, partly because the books found only in the Greek version were often used to justify doctrines he opposed, most notably prayer for the dead in the books of Maccabees. The seven books in question are called the deuterocanonical books: Tobit, Judith, Wisdom, Sirach, Baruch and the two books of Maccabees.

One further point: Catholicism does not hold to Scripture alone. It recognises two sources of revelation, Scripture and Sacred Tradition, the living tradition of the Church, and it holds that the authority to interpret them officially belongs to the hierarchy. In Vietnam the most widely used translation is the one produced by the Liturgy of the Hours Translation Group.

IXLiturgy and the Mass

The Mass is the central act of Catholic worship, celebrated every day in hundreds of thousands of churches around the world according to the same pattern. Catholics are obliged to attend Mass on Sundays and on holy days of obligation. Before the Second Vatican Council the Mass was said in Latin. Since the council, the liturgy has been celebrated in local languages.

Structure of the Mass

The Mass has four parts. The Introductory Rites include the entrance hymn, the sign of the cross, the greeting, the penitential act and the opening prayer. The Liturgy of the Word includes readings from Scripture with a responsorial psalm between them, the Gospel, the homily, the Creed and the prayers of the faithful. The Liturgy of the Eucharist includes the preparation of the gifts, the Eucharistic Prayer with the consecration at its heart, then the Communion rite with the Lord's Prayer and the receiving of Communion. Last come the Concluding Rites.

The liturgical year

Catholicism has its own calendar, the liturgical year, which begins not in January but on the first Sunday of Advent, usually in late November or early December, and ends with the feast of Christ the King.

The Rosary and popular devotions

Alongside the official liturgy there is a whole layer of practice that the Church calls popular piety. The best known is the Rosary, in which beads are counted while prayers are recited and twenty mysteries from the lives of Jesus and Mary are meditated on, grouped into four sets, the Joyful, Luminous, Sorrowful and Glorious. The Luminous Mysteries were added by Pope John Paul II in the apostolic letter Rosarium Virginis Mariae in 2002. In Vietnam these practices are woven into the rhythm of the Catholic village: evening prayers said together as a family, the chanted meditation on the fifteen sorrows of the Passion during Lent, processions in honour of Our Lady in May and October, and pilgrimages to La Vang.

XFour hundred years in Vietnam

Catholicism reached Vietnamese soil earlier than many people think. The history page of the Catholic Bishops' Conference of Vietnam gives the first date as 1533, when a missionary recorded as I Ni Khu (Inêkhu) came to preach in the villages of Ninh Cường and Quần Anh in Nam Chân district and Trà Lũ in Giao Thủy district, in what is now the Nam Định area. In the second half of the sixteenth century, Dominican and Franciscan priests came and went, and in 1573 a man named Đỗ Hưng Viễn is counted as the first Vietnamese believer.

The Jesuit missionaries and chữ Quốc ngữ

The turning point came in 1615, when Jesuit missionaries arrived in Đàng Trong (the southern realm) with a policy of cultural adaptation: learning the local language, wearing local dress, and expressing doctrine in the local people's own frame of ideas. To learn Vietnamese quickly, they used the Latin alphabet to write down the spoken sounds, and out of that practical need chữ Quốc ngữ, the romanised Vietnamese script, took shape.

This is a point that needs to be stated accurately, because it has long been shortened to a single name. The pioneer was Father Francisco de Pina, a Portuguese, who died in 1625. After him, Gaspar do Amaral and Antonio Barbosa compiled Vietnamese-Portuguese vocabularies. Alexandre de Rhodes, active in Vietnam in two periods, 1624 to 1630 and 1640 to 1645, was the one who inherited and systematised their work. In 1651 in Rome he printed the Vietnamese-Portuguese-Latin Dictionary and the Phép giảng tám ngày (the Eight-Day Catechism). To say he made a great contribution is correct. To say he single-handedly invented chữ Quốc ngữ is not.

Early structure and the periods of prohibition

In 1659 the Holy See established the first two apostolic vicariates on Vietnamese soil, one for Đàng Trong and one for Đàng Ngoài (the southern and northern realms). This is the legal birth date of the Church in Vietnam. In 1668 the first four Vietnamese priests were ordained, and in the same period the congregation of the Lovers of the Holy Cross was founded.

That history passed through many periods when the religion was prohibited, stretching from the time of the Trịnh and Nguyễn lords to the Nguyễn dynasty, most intensely between 1833 and 1861 under the reigns of Minh Mạng, Thiệu Trị and Tự Đức, each period with its own measures, such as the 1861 edict of "phân sáp" (dispersing Catholic families among non-Catholic villages). Earlier, in 1798, under the reign of Cảnh Thịnh, an edict of prohibition drove the Catholics of Quảng Trị into the forest of La Vang. From that event grew the tradition of an apparition of Our Lady, and La Vang was designated the National Marian Centre in 1961. The library reports these dates descriptively and assigns responsibility to no side.

The Vietnamese Martyrs

On 19 June 1988, Pope John Paul II canonised 117 martyrs of Vietnam, who had been beatified in four groups in the years 1900, 1906, 1909 and 1951. Among the 117 are 96 Vietnamese, comprising 37 priests, 14 catechists, 1 seminarian and 44 lay people, among them one woman, Agnes Lê Thị Thành, together with 11 of Spanish origin and 10 of French origin. The catechist Andrew Phú Yên was beatified on 5 March 2000. The number of people who died for the faith in the eighteenth and nineteenth centuries is far larger. Church documents usually give figures from 130,000 to 300,000, which should be understood as estimates.

The hierarchy and the Church today

In 1933, Bishop John Baptist Nguyễn Bá Tòng became the first Vietnamese bishop. In 1960, Pope John XXIII established the Vietnamese hierarchy with three ecclesiastical provinces, Hà Nội, Huế and Sài Gòn, ending the status of mission territory. The twenty-seventh diocese, the Diocese of Hà Tĩnh, was created in 2018. According to the 2025 statistics of the Catholic Bishops' Conference of Vietnam, as of 31 December 2025 Vietnam had about 7.57 million Catholics in a population of roughly 102.3 million, or about 7.4 percent, organised in 27 dioceses within 3 ecclesiastical provinces, with 8,307 priests, 4,636 seminarians, 28,493 religious brothers and sisters and 84,464 catechists.

XIOur Lady and the saints

Step into a Catholic church in Vietnam and you will see a statue of the Virgin Mary to one side of the sanctuary or out in the courtyard, sometimes larger than the crucifix itself, and there are always fresh flowers before it. That is the sign of something that runs deep in the life of the faith, but it is also the point outsiders misunderstand most.

The role of Mary

Catholicism professes that Mary is the woman who gave birth to Jesus, and because Jesus is God incarnate, the Church calls her the Mother of God. The title does not mean that she existed before God or that she gave birth to the divine nature. It is the logical consequence of professing Jesus as one single Person who is both God and man.

Veneration of the saints

A saint in Catholicism is a person who has died and whom the Church has confirmed to be in blessedness with God, after a long process of investigation called a cause for canonisation. The faithful ask the saints to intercede, that is, to pray to God on their behalf. Every parish takes a saint as its patron, and every person receives a saint's name at baptism.

This is the point that must be settled clearly, and the Church has three Latin words ready for it. Latria is adoration, reserved for the Holy Trinity alone and absolutely never given to anyone else. Dulia is veneration, given to the saints and the angels. Hyperdulia is the higher veneration reserved for the Virgin Mary, but it still belongs to the category of veneration, and the difference between the two categories is one of kind, not of degree.

In plain words: Catholics do not worship Mary and do not worship the saints. They honour them and ask for their prayers, while adoration is offered to God alone. The same applies to images: the Council of Nicaea in 787 defined that honour paid to an image is directed to the person it depicts and does not stop at the wood and stone. The most common mistake is to take the Vietnamese word thờ (worship) and apply it to every gesture of reverence. To ask the question correctly, ask a Catholic to whom the Mass is offered. The answer is always: to God.

XIINumber of adherents

Figures about religion always need to be read with attention to the source and the year. The Church's figures are based on the baptismal registers of the parishes, while the state statistics office counts by what people declare, so the two sides usually differ.

A few observations drawn from the table. First, Catholicism is the largest organised religious community in the world by number of adherents, and its current growth comes mainly from Africa, where the number of faithful rose from 281 to 288 million in a single year. Second, in Vietnam it is the second largest organised religion after Buddhism, at about seven percent of the population, a share that has been fairly stable over several decades. Third, the number of priests worldwide is nearly flat while the number of lay faithful grows.

XIIIThrough the eyes of feng shui

The most important thing is this: Catholicism does not teach feng shui, and the Church has an explicit position on divination. The Catechism of the Catholic Church, in paragraphs 2116 and 2117, states plainly that all forms of divination are to be rejected, naming astrology, palm reading, the interpretation of omens and the consulting of spirits, because such practices conceal a desire for power over time and over other people and weaken one's trust in God. Vietnamese Catholic question-and-answer sites apply this paragraph directly to horoscope reading. From the standpoint of the religion itself, 風水 is no part of the faith. The library states this first so that no one reads this section and comes away thinking Catholics ought to consult feng shui.

Yet Vietnamese churches are built in the local manner

That is the matter of doctrine. Building on Vietnamese soil is a different matter, one that can be observed with the eyes: over four hundred years, most churches in Vietnam were built by Vietnamese craftsmen, using the skills those craftsmen had learned from building communal houses and pagodas.

The clearest example is the Phát Diệm stone cathedral complex in Ninh Bình, built under the direction of Father Peter Trần Lục, known locally as Cụ Sáu, in the late nineteenth century, with the main church raised in 1891. The southern approach opens onto a broad pond with a small island in the middle. Beyond the pond stands the Phương Đình, a three-storey stone block structured like the three-arched gate of a Vietnamese communal house or pagoda, with curved roofs and carved ornament in the East Asian style. The same pattern appears elsewhere: a wide forecourt, many buildings facing south, and an enclosing wall with a three-arched gate.

Three layers to keep apart

The first layer, what the Church teaches. The rules on church architecture speak of liturgy, not of energy fields: the sanctuary must stand out, the altar is the centre, then the ambo, the tabernacle and the baptismal font. The ancient tradition of orienting churches towards the east carries the meaning of turning towards the risen Christ. That is liturgical symbolism, not a method of choosing a direction according to the owner's birth year.

The second layer, what craftsmen and local people did out of building habit. This is where the features that outsiders take for feng shui actually come from. The carpenter who raised a church was the carpenter who had raised communal houses. The pond in front, the wide courtyard, the curved roofs, the three-arched gate and the southern orientation came from craft and climate, not from any article of canon law.

The third layer, the library's own reading. The overlap between the two layers above is not accidental, because traditional feng shui and folk building experience both draw on the same set of conditions: the north-east monsoon, the harsh southern sun, heavy rain and low-lying land. This is an interpretation, not a teaching of the Church.

XIVCommon misunderstandings

This last section gathers the questions the library hears most often when people outside the faith ask about Catholicism. The three most common slips: confusing Catholicism with Protestantism because both are Christian, confusing veneration with worship because Vietnamese uses one word, thờ, for both, and confusing the Church's discipline, which can change, with its dogma, which does not.

?Quick Questions

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