Holiness, or sanctity, is in general the state of being holy (perceived by religious individuals as associated with the divine) or sacred (considered worthy of spiritual respect or devotion; or inspiring awe or reverence among believers in a given set of spiritual ideas). In other contexts, objects are often considered 'holy' or 'sacred' if used for spiritual purposes, such as the worship or service of gods. These terms can also be used in a non-spiritual or semi-spiritual context ("sacred truths" in a constitution). It is often ascribed to people ("a holy man" of religious occupation, "holy prophet" who is venerated by his followers), objects ("sacred artifact" that is worshipped), times ("holy days" of spiritual introspection, such as during winter holidays), or places ("sacred ground", "holy place").

Etymology

The word "sacred" descends from the Latin sacrum, which referred to the gods or anything in their power, and to sacer, priest; sanctum, set apart. It was generally conceived spatially, as referring to the area around a temple.

The English word holy dates back to at least the 11th Century with the Old English word hālig, an adjective derived from hāl meaning whole and used to mean 'uninjured, sound, healthy, entire, complete’. The Scottish 'hale' (health, happiness and wholeness.) is the most complete modern form of this Old English root. The modern word 'health' is also derived from the Old English hal. As “wholeness”, holiness may be taken to indicate a state of religious completeness or perfection. The word holy in its modern form appears in Wyclif's Bible of 1382.

In non-specialist contexts, the term "holy" is used in a more general way, to refer to someone or something that is associated with a divine power, such as water used for Baptism.

Holiness in Judaism

The Hebrew word for "holiness," "kedushah" () has the connotation of "separateness." That which is holy in Judaism is set apart, and the separation is maintained by both legal and spiritual measures.
Certain places and times are intrinsically sacred, and strictures are placed on one's actions in those situations. However, holiness is not a single state, but contains a broad spectrum. The Mishnah lists concentric circles of holiness surrounding the Temple in Jerusalem: Holy of Holies; Temple Sanctuary; Temple Vestibule; Court of Priests; Court of Israelites; Court of Women; Temple Mount; the walled city of Jerusalem; all the walled cities of Israel; and the borders of the Land of Israel. Distinctions are made as to who and what are permitted in each area. Likewise, the holidays, including and especially the Sabbath, are considered to be holy in time; the Torah calls them "holy [days of] gathering. Work is not allowed on those days, and rabbinic tradition lists 39 categories of activity that are specifically prohibited.

The Torah describes the Aaronite priests and the Levites as being selected by God to perform the Temple services; they, as well, are called "holy." A righteous person (tzadik) is also considered to be holy.

Beyond the intrinsically holy, objects can become sacred through consecration. Any personal possession may be dedicated to the Temple of God, after which its misappropriation is considered among the gravest of sins. The various sacrifices are holy; those which may be eaten have very specific rules concerning who may eat which of their parts, and time limits on when the consumption must be completed. Most sacrifices contain a part to be consumed by the priests - a portion of the holy to be consumed by God's holy devotees.

The encounter with the holy is seen as eminently desirable, and at the same time fearful and awesome. For the strongest penalties are applied to one who transgresses in this area - one could in theory receive either the death penalty or the heavenly punishment of karet, spiritual excision, for mis-stepping in his close approach to God's domain.

Holiness in Christianity

Holiness in Catholicism

Catholicism has inherited much of the Jewish vision of the world in terms of holiness, with certain behaviour appropriate to certain places and times. The calendar gives shape to Catholic practice, which tends to focus on the Eucharist, in which the Real Presence of Christ is manifested. Holy days, celebrating Catholic saints and events of the life of Christ are celebrated throughout the year. Many features of the Jewish temple(although now seen as having Christian significance) are imitated in churches, such as the altar, bread, lamp, incense, font, etc, to emphasise the extreme holiness of the Eucharistic elements, which are reserved in a tabernacle. In extension of this focus on the Sacrament as holy, many objects in Catholicism are also considered holy. They are called sacramentals and are usually blessed by a priest. Such items include rosaries, crucifixes, medals, and statues and icons of Jesus, angels and saints (Virgin Mary). While Catholics believe that holy places and objects (i.e., objects dedicated to God for sacred use) should be respected and not put to profane use, the Catholic Church condemns worshiping the object itself, as any worship given to something other than God is considered idolatry.

People in a state of sanctifying grace are also considered holy in Catholicism. A central notion of Catholicism as articulated in contemporary theology is the "[personal] call to holiness," considered as a vocation shared by every Christian believer. Profound personal holiness has traditionally also been seen as a focus for the kind of contagious holiness primarily associated with the Sacrament. So the communion of saints in Catholicism is not only the acclamation of their piety or morality, but also reverence for the tangible holiness that flows from their proximity to the divine. Hence the places where saints lived, died, performed miracles, or received visions frequently become sites of pilgrimage, and notable objects surviving a saint (including the body or parts of it) are considered relics. The holiness of such places or objects, resulting from contact with a deeply holy person, is often connected with the miraculous long after the death of the saint.
Sanctus is the name of an important hymn of Christian liturgy. The Trisagion ('Thrice Holy') is a standard hymn of the Divine Liturgy of the Eastern Churches.

Holiness in Protestantism

The Protestant Reformation stood in opposition to the beliefs of tangible holiness in the Catholic Church and rejected most of its teachings regarding devotional practice, language and imagery. The early Protestant Reformers, who were often scholars of Ancient Greek and also borrowed from Jewish scholarship, recognized that holiness is an attribute of God, and holiness is always part of the presence of God. Yet they also recognized that practical holiness was the evidence of the presence of God in the converted believer. Martin Luther viewed God's grace (and therefore God's holiness), as an invasion of the life. Actions that demonstrated holiness would spring up, not premeditated, as the believer focused more and more on his or her relationship with Christ. This was the life of faith, according to Luther, a life in which one recognizes that the sin nature never departs, yet grace invades and draws the person after Christ.
Calvin, on the other hand, formulated a practical system of holiness that even tied in with culture and social justice. All unholy actions, Calvin reasoned, resulted in suffering. Thus he proved out to the city fathers of Geneva that dancing and other social vices always ended with the wealthy oppressing the poor. A holy life, in his outlook, was pietistic and simple, a life that shunned extravagance, excess, and vanity. On a personal level, Calvin believed that suffering would be a manifestation of taking on the Cross of Christ, but suffering was also part of the process of holiness. He expected that all Christians would suffer in this life, not as punishment, but rather as participation in union with Christ, who suffered for them. And yet, socially, Calvin argued that a holy society would end up as a gentle, kindly society (except to criminals) where the poor would be protected from the abuses of the wealthy, the lawyers, and others who normally preyed upon them.

In Protestantism, especially in American branches of Protestantism of the more Pentecostal variety, holiness has acquired the secondary meaning of the reshaping of a person through spiritual rebirth. The term owes its origin to John Wesley's concept of "scriptural holiness" or Christian perfection.

The Holiness movement began within Methodism in the United States, among those who thought the church had lost the zeal and emphasis on personal holiness of Wesley's day. In the latter part of the 19th century revival meetings were held, attended by thousands. In Vineland, N.J in 1867 a camp meeting was begun and the National Holiness Camp Meeting Association, which went on to establish many holiness camp meetings across the nation. Some adherents to the movement remained within their denominations; others founded new denominations, such as the Free Methodist Church, the Church of the Nazarene, and the Church of God (Anderson). Within a generation another movement, the Pentecostal movement was born, drawing heavily from the Holiness Movement. Around the middle of the 20th century, the Conservative Holiness Movement was born - a conservative offshoot of the Holiness movement.

The Higher Life movement appeared in the British Isles during the mid 1800's.

In the contemporary Holiness movement, the idea that holiness is relational is growing. In this thought, the core notion of holiness is love. Other notions of holiness, such as purity, being set apart, perfection, keeping rules, and total commitment, are seen as contributory notions of holiness. These contributory notions find their ultimate legitimacy when love is at their core (Thomas Jay Oord and Michael Lodahl).

Commonly recognized outward expressions or "standards" of holiness among more fundamental adherents frequently include applications relative to dress, hair, and appearance: e.g., short hair on men, uncut hair on women, and prohibitions against shorts, pants on women, make-up and jewelry. Other common injunctions are against places of worldly amusement, mixed swimming, smoking, minced oaths, as well as the eschewing of television and radio.

More traditional or mainline Protestant denominations, such as the Anglican, Lutheran, and some Methodist denomninations, believe in Holy Sacraments that the clergy perform, such as Holy Communion and Holy Baptism. As well as strong belief in the Holy Catholic Church, Holy Scripture, Holy Trinity, and the Holy Covenant. They also believe that angels and saints are called to holiness.

Holiness in Buddhism

In Theravada Buddhism one finds the designation of 'noble person' or ariyapuggala (Pali). The Buddha described four grades of such person depending on their level of purity. This purity is measured by which of the ten fetters (samyojana) and klesha have been purified and integrated from the mindstream. These persons are called (in order of increasing sanctity) Sotapanna, Sakadagami, Anagami and Arahant. The latter term designates an enlightened human being and is sometimes rendered into English as the Holy One.

Hierology

Hierology (Greek ιερος, hieros, "sacred" or "holy", + λογος, logos, "word" or "reason") refers to the study of the sacred and sacredness. It is generally pursued by those who find real truth in many faiths and especially refers to philosophical speculations about religion that involve the traditions of multiple cultures or belief systems. It differs from theology in that a god or gods are not necessarily a focus and in that it may include sources with no origin in Western philosophy or religion.

Sacred ground

Sometimes a social or religious group considers an area sacred or holy, e.g. a cemetery. See also most sacred sites.