holy water, in Christianity, water that has been blessed by a member of the clergy and is used in baptism and to bless individuals, churches, homes, and articles of devotion. A natural symbol of purification, water has been used by religious peoples as a means of removing uncleanness, either ritual or moral. Holy water is used in Roman Catholicism, Eastern Orthodoxy, certain Lutheran synods, Anglicanism, and various other churches.

In the early Christian community the “living” water of rivers and streams was preferred for baptism and apparently received no special blessing. By the time of the 4th century the still waters of the baptismal font or pool were exorcised and blessed with the sign of the cross. Other water was blessed for the use of the faithful as a means of warding off the unclean spirit and as a safeguard against sickness and disease. In the course of time, this blessed, or holy, water was used as a reminder of baptism by the faithful on entering the church and by the celebrant in sprinkling the congregation before certain Sunday masses. In Eastern Orthodoxy, holy water is commonly imbibed by the faithful after it has been blessed.