Baptism (from Koine Greek: βάπτισμα, romanized: váptisma, lit. 'immersion, dipping in water')^[1] is a Christian rite of initiation almost invariably with the use of water.^[2][3] It may be performed by sprinkling or pouring water on the head, or immersing in water (partially or completely), traditionally three times for each person of the Trinity.^[4][5][6] It is also called christening,^[7][8] although this is typically reserved for the baptism of infants.^[9] Baptism is regarded as a sacrament in most churches and an ordinance in others. The synoptic Gospels recount that John the Baptist baptized Jesus.^{[10][11][12][13]}

Baptism according to the Trinitarian formula, which is done in most mainstream Christian denominations, is seen as being a basis for ecumenism, the concept of unity among Christians.^[14][15][16] In certain Christian denominations, such as the Catholic Church, Eastern Orthodox Church, Oriental Orthodox Churches, Assyrian Church of the East, and Lutheran churches, baptism is the door to church membership, with candidates taking baptismal vows.^[17][18] It has also given its name to the Baptist churches and denominations.

Certain schools of Christian thought (such as Catholic and Lutheran theology) regard baptism as necessary for salvation (though not without exception^[19]), but some writers, such as Huldrych Zwingli (1484–1531), have denied its necessity.^[20] Though water baptism is extremely common among Christian denominations, some, such as Quakers, some Unitarians (in particular Unitarian Universalists), and the Salvation Army, do not practice water baptism at all.^[21][22] Among denominations that practice baptism, differences occur in the manner and mode of baptizing and in the understanding of the significance of the rite. Most Christians baptize using the Trinitarian formula "in the name of the Father, and of the Son, and of the Holy Spirit"^[23] (following the Great Commission), but Oneness Pentecostals baptize using Jesus' name only.^[24] The majority of Christians baptize infants;^[a] many others, such as Baptist churches, regard only believer's baptism as true baptism.^[25] In certain denominations, such as the Eastern and Oriental Orthodox Churches, the individual being baptized receives a cross necklace that is worn for the rest of their life, inspired by the Third Council of Constantinople.^[26][27]

There are three modes of baptism: sprinkling, affusion, and immersion, though the use of each mode varies by Christian denomination. A specific form of baptism by immersion, known as trine immersion consists of "the dipping of the candidate in the water three times-first, in the name of the Father, second, in the name of the Son, and, third, in the name of the Holy Spirit."^[28] In the present day, trine immersion is practiced by the River Brethren and Schwarzenau Brethren, as well as by parts of the Eastern Orthodox Church.^[28]

The term baptism has also been used metaphorically to refer to any ceremony, trial, or experience by which a person is initiated, purified, or given a name.^[29] Martyrdom was identified early in Christian church history as "baptism by blood", enabling the salvation of martyrs who had not been baptized by water. Later, the Catholic Church identified a baptism of desire, by which those preparing for baptism who die before actually receiving the sacrament are considered saved.^[30] In the Methodist tradition, baptism with the Holy Spirit, has referred to the second work of grace, entire sanctification; in Pentecostalism, baptism with the Holy Spirit is identified with speaking in tongues.^[31]

Outside of Christianity, Mandaeans undergo repeated baptism for purification instead of initiation.^[32] They consider John the Baptist to be their greatest prophet and name all rivers yardena after the Jordan River.^{[32][33][34]: 45}

The English word baptism is derived indirectly through Latin from the neuter Greek concept noun báptisma (Greek βάπτισμα, 'washing, dipping'),^[b][35] which is a neologism in the New Testament derived from the masculine Greek noun baptismós (βαπτισμός), a term for ritual washing in Greek language texts of Hellenistic Judaism during the Second Temple period, such as the Septuagint.^[36][37] Both of these nouns are derived from the verb baptízō (βαπτίζω, 'I wash' transitive verb), which is used in Jewish texts for ritual washing,^[38] and in the New Testament both for ritual washing and also for the apparently new rite of báptisma.

The Greek verb báptō (βάπτω), 'dip', from which the verb baptízō is derived, is in turn hypothetically traced to a reconstructed Indo-European root *gʷabh-, 'dip'.^[39][1][40]

The Greek words are used in a great variety of meanings.^[41] βάπτω and βαπτίζω in Hellenism had the general usage of "immersion", "going under" (as a material in a liquid dye) or "perishing" (as in a ship sinking or a person drowning), with the same double meanings as in English "to sink into" or "to be overwhelmed by", with bathing or washing only occasionally used and usually in sacral contexts.^[42]

The practice of baptism emerged from Jewish ritualistic practices during the Second Temple Period, when figures such as John the Baptist emerged. At that time, Jewish ritual immersion was rooted in the purification practices prescribed in the Hebrew Bible, such as those described in Leviticus 15. This immersion (tevilah) was practiced in a ritual bath known as a mikveh or in natural bodies of water, including rivers. For example, various texts in the Dead Sea Scrolls (DSS) corpus at Qumran describe ritual practices involving washing, bathing, sprinkling, and immersing. One example of such a text is a DSS known as the Community Rule, which says "And by the compliance of his soul with all the laws of God his flesh is cleansed by being sprinkled with cleansing waters and being made holy with the waters of repentance."^[43]

The Mandaeans, who are followers of John the Baptist, practice frequent full immersion baptism (masbuta) as a ritual of purification.^[44] According to Mandaean sources, they left the Jordan Valley in the 1st century AD.^[45]

John the Baptist, who is considered a forerunner to Christianity, used baptism as the central sacrament of his messianic movement.^[46] The apostle Paul distinguished between the baptism of John, ("baptism of repentance") and baptism in the name of Jesus,^[47] and it is questionable whether Christian baptism was in some way linked with that of John.^[48] However, according to Mark 1:8, John seems to connect his water baptism as a type of the true, ultimate baptism of Jesus, which is by the Spirit. Christians consider Jesus to have instituted the sacrament of baptism.^[20]

Though some form of immersion was likely the most common method of baptism in the early church, many of the writings from the ancient church appeared to view this mode of baptism as inconsequential. The Didache 7.1–3 (AD 60–150) allowed for affusion practices in situations where immersion was not practical. Likewise, Tertullian (AD 196–212) allowed for varying approaches to baptism even if those practices did not conform to biblical or traditional mandates (cf. De corona militis 3; De baptismo 17). Finally, Cyprian (ca. AD 256) explicitly stated that the amount of water was inconsequential and defended immersion, affusion, and aspersion practices (Epistle 75.12). As a result, there was no uniform or consistent mode of baptism in the ancient church prior to the fourth century.^[49]

By the third and fourth centuries, baptism involved catechetical instruction, chrismation, exorcisms, laying on of hands, and recitation of a creed.^[50]

In the Early Middle Ages, infant baptism became common and the rite was significantly simplified and increasingly emphasized.^[51][52] In Western Europe Affusion became the normal mode of baptism between the twelfth and fourteenth centuries, though immersion was still practiced into the sixteenth.^[53] In the medieval period, some radical Christians rejected the practice of baptism as a sacrament. Sects such as the Tondrakians, Cathars, Arnoldists, Petrobrusians, Henricans, Brethren of the Free Spirit, and the Lollards were regarded as heretics by the Catholic Church. In the sixteenth century, Martin Luther retained baptism as a sacrament,^[54] but Swiss reformer Huldrych Zwingli considered baptism and the Lord's Supper to be symbolic.^[20] Anabaptists denied the validity of the practice of infant baptism, and rebaptized converts.^[55]

Baptism is practiced in several ways. Aspersion is the sprinkling of water on the head, and affusion is the pouring of water over the head.^[4] Traditionally, a person is sprinkled, poured, or immersed three times for each person of the Holy Trinity, with this ancient Christian practice called trine baptism or triune baptism.^[4][6] The Didache specifies:

This is how you should baptize: Having recited all these things, [the first half of the Teaching, "The Way of Life and the Way of Death"] baptize in the name of the Father and the Son and the Holy Spirit, in running water. If you do not have running water, then baptize in still water. The water should be cold, but if you do not have cold water, then use warm. If you have neither, then just pour water on the head three times in the name of the Father, the Son, and the Holy Spirit. Both the one who is baptized and the one who baptizes should fast beforehand, along with any others who are able, the one that is baptized being told to fast for a day or two.^[56]

The word "immersion" is derived from Late Latin immersio, a noun derived from the verb immergere (in – "into" + mergere "dip"). In relation to baptism, some use the term to refer to any form of dipping, whether the body is put completely under water or only partially dipped in water. They thus speak of immersion as being either total or partial. Others, particularly within the Anabaptist traditions, use "immersion" to refer exclusively to plunging someone entirely under the surface of the water.^[57][58] The term "immersion" is also used of a form of baptism in which water is poured over someone standing in water, without fully submerging the person.^[59][60] For the three different meanings of the word "immersion", see Immersion baptism.

When "immersion" is used in opposition to "submersion",