this: the Christian religious ceremony of Baptism and other water-related religious practices

In Christianity, baptism (from Greek baptizo: "immersing", "performing ablutions") is the ritual act, with the use of water, by which one is admitted as a full member of the Christian Church and, in the view of some, as a member of the particular Church in which the baptism is administered.

Some Christians, particularly Quakers and the Salvation Army, do not see baptism as necessary. Among those that do, differences can be found in the manner of baptizing and in the understanding of the significance of the rite. Most baptize "in the name of the Father, and of the Son, and of the Holy Spirit" (following the Great Commission), but some baptize in Jesus' name only. Most baptize infants, others do not. Some insist on submersion or at least partial immersion of the person who is baptized, others consider that any form of washing by water is sufficient.

The usual form of baptism among the earliest Christians was for the candidate (or "baptizand") to be immersed totally or partially. While John the Baptist's use of a deep river for his baptism suggests immersion, pictorial and archaeological evidence of Christian baptism from the 3rd century onwards indicates that the normal form was to have the candidate stand in water while water was poured over the upper body. Other common forms of baptism now in use include pouring water three times on the forehead.

Baptism was seen as in some sense necessary for salvation, until Huldrych Zwingli in the sixteenth century denied its necessity. Martyrdom was identified early in church history as baptism by blood, enabling martyrs who had not been baptized by water to be saved. 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.

The English word "baptism" has been used in reference to any ceremony, trial, or experience by which one is initiated, purified, or given a name. See Other initiation ceremonies below.

Meaning of the word in the New Testament

As Christians of different traditions dispute whether total immersion (submersion) is necessary for baptism, the precise meaning of the Greek word has become important for exegesis.

The Greek-English Lexicon of Liddell and Scott gives the primary meaning of the word (transliterated as "baptizô"), from which the English word baptism is derived, as dip, plunge, but indicates, giving Luke 11:38 as an example, that another meaning is perform ablutions.