Baptism
From dKosopedia
In the Christian tradition, baptism is a rite of membership in the church, linked to the Baptism of Jesus by John the Baptist in the Gospels found in the Bible.
Liturgical churches with ancestral roots in the Roman Catholic Church or early Reformation churches usual baptize infants by annointing them with oil and/or water. Baptist churches and a number of other non-liturgical churches typically baptize adults only, and often do so by immersion (i.e. by having the presiding clergyman dunk the person to be baptized in a pool or river of water).