Baptism (from Koinē Greek: βάπτισμα, romanized: váptisma) is a form of ritual purification—a characteristic of many religions throughout time and geography. In Christianity, it is a Christian sacrament of initiation and adoption, almost invariably with the use of water. It may be performed by sprinkling or pouring water on the head, or by immersing in water either partially or completely, traditionally three times, once for each person of the Trinity. The synoptic gospels recount that John the Baptist baptised Jesus. Baptism is considered a sacrament in most churches, and as an ordinance in others. Baptism according to the Trinitarian formula, which is done in most mainstream Christian denominations, is seen as being a basis for Christian ecumenism, the concept of unity amongst Christians.