The rite of initiation for Christians, in which water is used to symbolise the washing away of sin and to welcome the person into the Christian church. For some Christians (such as Roman Catholics), this is usually paedobaptism, which is the baptising of a baby or child usually by pouring a small amount of water over their head, at a font, three times in the name of the Trinity (Father, Son, and Holy Spirit). Other Christians (such as Baptists) prefer adult baptism, or believer’s baptism, which usually involves full immersion of the person into a baptistery or pool.