|The Easter Vigil, also called the Paschal Vigil or the Great Vigil of Easter, is a service held in many Christian churches as the first official celebration of the Resurrection of Jesus. Historically, it is during this service that people (especially adults) are baptized and that adult catechumens are received into full communion with the Church. It is held in the hours of darkness between sunset on Holy Saturday and sunrise on Easter Day—most commonly in the evening of Holy Saturday—but is considered to be the first celebration of Easter Day, since the Christian tradition considers feasts and other days of observance where Masses are celebrated to begin at sunset of the previous day.
In the Roman Catholic Church and the Anglican Communion, the Easter Vigil is the most important Mass of the liturgical year as well as the first celebration of the Eucharist during the fifty-day long celebration of Easter, and is marked by the first use since the beginning of Lent of the acclamatory word "Alleluia", a distinctive feature of the liturgy of the Easter season. Similarly, in Eastern and Oriental Orthodoxy, the Divine Liturgy which is celebrated during the Easter Vigil is the most elaborate and important of the ecclesiastical year. The Easter Vigil has enjoyed a substantial revival among the Lutherans.