Lay religious personnel

In religious organizations, the laity comprises all lay persons collectively. This can mean either any person who is not a member of the ordained clergy or of any monastic order or, within such an order, a monastic who is not a priest (c.f., lay brother). Conversely, terms such as lay priest, lay clergy and lay nun were once used in both Christian and Buddhist cultures to indicate ordained persons who continued to live out in the wider community instead of retiring to a monastery. In recent centuries, the term is often used more generally, in the context of any specialized profession, to refer to those who are not members of that profession.

The word lay derives from the Anglo-French lai (from Late Latin laicus, from the Greek λαϊκός, laikos, of the people, from λαός, laos, the people at large).

Christian laity
In Anglicanism, the term "laity" refers either to anyone who is not a priest or deacon, or to the third order of ministers in the Church. In the Anglican tradition, all baptised persons are considered to be called to minister in Christ's name. The three orders of ministry are Priests, Deacons, and Lay Persons.

The ministry of the laity is "to represent Christ and his Church; to bear witness to him wherever they may be; and, according to the gifts given them, to carry on Christ's work of reconciliation in the world; and to take their place in the life, worship, and governance of the Church".

There are elected lay representatives on the various governing bodies of churches in the Anglican communion. In the Church of England, a member of the Anglican communion, these governing bodies range from a local Parochial Church Council, through Deanery Synods and Diocesan Synods. At the topmost level, the General Synod includes a house of Laity.

As a member of the Anglican Communion, The Episcopal Church shares the Anglican view of lay persons as the third order of ministers in the Church. The Canons of the Episcopal Church provide for six types of licensed lay ministers: Pastoral Leader, Worship Leader, Preacher, Eucharistic Minister, Eucharistic Visitor, and Catechist. Persons serving in these positions are licensed by the Bishop of the applicable Diocese.

Lay people serve in worship services in a number of other important, but unlicensed positions, including: vergers, acolytes, and lay readers (also called "lectors").

In many parishes, a verger is appointed by the rector.

In some parishes, the rector appoints a special Acolyte Master who selects and supervizes the acolytes. Acolyte positions include torch bearer (carries the torches), crucifer (carries the cross), thurifer (carries the brass thurible with coals and incense),and boat boy or boat girl (carries the extra incense).

Lectors or lay readers, as the name implies, may read the lessons from the Bible appointed for the day (except for the Gospel reading, which is read by a Deacon), and may also lead the "Prayers of the People."

In the Episcopal Church the laity can have say in legislation. At General Convention up to four lay persons from each diocese are elected to represent the diocese in the House of Deputies, one of the two governmental houses in the Episcopal Church. On the local parish level, lay persons are elected to a church council called a vestry.

Roman Catholicism
In Catholicism, the term lay has two distinct meanings. The primary meaning refers to those faithful who have not received Holy Orders, whether living in religious orders or in the world. A secondary meaning refers to those who do not live in religious orders (thus, diocesan priests are sometimes called secular priests). In official documents, the term, laity, typically refers to the non-ordained.

Paragraph 31 of the dogmatic constitution Lumen Gentium defines the laity as follows: The term laity is here understood to mean all the faithful except those in holy orders and those in the state of religious life specially approved by the Church. These faithful are by baptism made one body with Christ and are constituted among the People of God; they are in their own way made sharers in the priestly, prophetical, and kingly functions of Christ; and they carry out for their own part the mission of the whole Christian people in the Church and in the world.

The Second Vatican Council taught that the laity's specific character is secularity, i.e. as Christians who live the life of Christ in the world, their role is to sanctify the created world by directing it to become more Christian in its structures and systems: "It belongs to the laity to seek the kingdom of God by engaging in the affairs of the world and directing them according to God's will," stated the Council in "Lumen Gentium." The laity are full members of the Church, who fully share in Church's purpose of sanctification, of "inner union of men with God," (CCC 775) acting with freedom and personal responsibility and not as mere agents of the hierarchy. Due to their baptism, they are members of God's family, the Church, and they grow in intimate union with God, "in" and "by means" of the world. It is not a matter of departing from the world as the monks and the nuns do that they sanctify themselves; it is precisely through the material world sanctified by the coming of the God made flesh, i.e. made material, that they reach God. Doctors, mothers of a family, farmers, bank tellers, drivers, by doing their jobs in the world with a Christian spirit are already extending the Kingdom of God. According to the repeated statements of Popes and lay Catholic leaders, the laity should say "we are the Church," in the same way that the saints said that "Christ lives in me."

Lay involvement has taken diverse forms including participation in the life of the parish, unions of prayer, confraternities, communes, guilds, lay apostolates, Catholic Action, secular institutes, and lay ecclesial movements.

The role of the laity in the Church includes lay ministers. Also, as a result of the priest shortage, members of the laity have had to take on some of the roles previously performed by priests.

Catholic Servant Leadership is an emerging trend designed to help develop leadership skills for both Catholic laity and vowed religious to meet the issues the Church faces in the 21st century.

The Lay Preacher in the Wesleyan / Methodist tradition
A very early tradition of preaching in the Wesleyan / Methodist churches was for a Lay Preacher to be appointed to lead services of worship and preach in a group (called a 'circuit') of meeting places or churches. The lay preacher walked or rode on horseback in a prescribed circuit of the preaching places according to an agreed pattern and timing, and people came to the meetings. After the appointment of ministers and pastors, this lay preaching tradition continued with  Local Preachers being appointed by individual churches, and in turn approved and invited by nearby churches, as an adjunct to the minister or during their planned absences.

In addition to being appointed by members of their local churches, Local and Certified  Lay Speakers of the United Methodist Church (more commonly in the United States) attend a series of training sessions. These training sessions prepare the individual to become a leader within the church. All individuals who are full members of the church are laity, but some go on to become Lay Speakers. Some preachers get their start as Lay Speakers.

In the Uniting Church in Australia, that was constituted in part from the Methodist Church, persons can be appointed:
 * by the congregation as a Lay Preacher; and/or
 * by the regional Presbytery to conduct Communion.

A well-known lay preacher was the late King Taufa'ahau Tupou IV of Tonga.

The comparable term in the Anglican and Episcopal churches is Lay Reader.

Buddhist lay persons
In Buddhism, a layperson is known as an upasaka (masc.) or upasika (fem.). Buddhist laypeople take refuge in the Triple Gem (the Buddha, his teaching, and his community of noble disciples) and accept the Five Precepts as rules for conduct. Laymen and laywomen are two of the "four assemblies" that comprise the Buddha's "Community of Disciples."

In Chinese Buddhism, there are usually laypersons, who are depicted wearing a black robe and sometimes a brown sash, denoting that they received the five precepts.

Laity as a surname
There are quite a number of people globally with Laity as a surname. This originates mainly from Cornish ancestry, with a great deal of emigration spreading the surname thinly across the globe.