In several religions, a rite of initiation and purification, performed with water, often involving submersion of the body.
The word comes from Greek baptein, "to immerse, submerge, dip".
Water was, no suprise, a central symbol of purifications across many religions from the earliest of times. Lands of important rivers, especially in lands where desert would have prevailed was it not for the river, like in Egypt and Babylonia, compex religious rituals developed. Their value was far more than just purification for the individual, it related to the whole structures of society. In Hellenistic mystery cults, sacred baths were central and independent of the river.
In Christianty, baptism is early on a symbol of the faith, and of Jesus himself. Jesus is told to have been baptized by John the Baptist. In Matthew 28:19, Jesus tells his disciples to baptize the nations as a sign of God's coming rule.
In Christianity, baptism is a one-time ceremony, marking the entry into the Christian faith. Baptism is a sacrament or sign of grace.
The New Testament has no clear instructions on how to physically administer the water of baptism. Questions over whether the body should be submerged in water, or if water should only be poured over the head appear to have been there ever since the early Christians. The 2nd century scripture, Didache, tells that baptism best is performed in "in living water. But if you have no living water, baptize into other water; and if you cannot do so in cold water, do so in warm. But if you have neither, pour out water three times upon the head into the name of Father and Son and Holy Spirit." The earliest baptism rituals were very simple, but became much elaborated during the 3rd century. This involved added, complex rituals to the actual baptism.
Another recurring issue is the age of the faithful being baptised. Infant baptism is believed to have been performed since the earliest times, but as many early Christians believed that sins committed after the baptism, could not be forgiven, most waited as long as they could to be baptized, often to their death beds. But the danger of dying unbaptized caused a slow reorientation, and the doctrines of sins committed after baptism as unforgivable was gradually softened. Since child mortality was common, infant baptism would make its return. Among those central, early theologians rejecting infant Baptism, was Tertullian.
The ritual of Baptism is performed in the name of the Trinity (Father, Son, and Holy Spirit) or in the name of Jesus Christ. In Orthodox churches and Eastern Catholics the whole body is immersed, while other churches pour or sprinkle water. Roman Catholics pour water over the head.
The Roman Catholic Church teaches that "baptism is necessary for salvation", and the person who knowingly and willfully rejects baptism has no hope of salvation.
St. Paul developed the concept of the baptism being the human participation in the death and resurrection of Christ (Romans 6:3-11), and also being the human reception of the gifts of the Holy Spirit. The early church came to understand baptism as a renunciation of the flesh and the devil.
In Judaism, the Jewish law allows the use of water in ritual cleansing. Moreover, the cleansing in water involves miraculous effects, as the 2 Kings 5, one hears of a case where dipping in the Jordan River should cleanse of leprosy.
Converts to Judaism had to bathe as a siymbol of entering the covenant. It was especially in the Jordan River that Jews in the need of remission of sin could be purified.
Rituals involving immersion in water has been important in Judaism, symbolizing purification or consecration. Traditionally, a Jew who somehow had been defiled, had to perform the cleansing ritual of mikvah before being allowed reentry into the Temple. But with the destruction of this, new understandings emerged. Today, only Orthodox and Haredi Jews demand the passing through of the mikvah.
Jewish converts are expected to pass through the mikvah in all types of Judaism.
With the Essenes, ritual immersion was an important ritual. The Essenes are often suggested as a forerunner of Christianity.
Baptism is central to the cult of Mandeans, using a pool which is connected to a nearby river. For the ritual, this river is called 'Jordan'. Baptisms are a weekly ceremony, performed on Sundays, and every believer pass through this several times every year. Mandean baptism can be compared to the Christian communion, and the Muslim prayer, salat.