Baptism

"In Christianity, baptism (from Greek βάπτισμα and βαπτισμός, meaning "immersing", "performing ablutions" - see below) is the sacramental act of cleansing in water that admits one as a full member of the Church. Most Christians, such as Roman Catholics, Eastern Orthodox, and Lutherans, are baptized as infants. Baptists and certain other groups baptize only after a person accepts Jesus Christ as their Savior ("believer's baptism"). Most Christians baptize in the name of the Father, Son, and Holy Spirit, but some baptize in Jesus' name only." via wikipedia