Ecclesiology (from Greek ἐκκλησίᾱ, ekklēsiā, "congregation, church"; and -λογία, -logia) is the study of the theological understanding of the Christian church. Specific areas of concern include the church's role in salvation, its origin, its relationship to the historical Christ, its discipline, its destiny, and its leadership. Ecclesiology is, therefore, the study of the church as a thing in itself.
Different ecclesiologies give shape to very different institutions. Thus, in addition to describing a broad discipline of theology, ecclesiology may be used in the specific sense of a particular church or denomination's character, self-described or otherwise. This is the sense of the word in such phrases as Roman Catholic ecclesiology, Lutheran ecclesiology, and ecumenical ecclesiology.
Ecclesiology comes from the Greek ἐκκλησία (ekklesia), which entered Latin as ecclesia. In the Greco-Roman world, the word was used to refer to a lawful assembly, or a called legislative body. As early as Pythagoras, the word took on the additional meaning of a community with shared beliefs. This is the meaning taken in the Greek translation of the Hebrew Scriptures (the Septuagint), and later adopted by the Christian community to refer to the assembly of believers.
Issues addressed by ecclesiology
Ecclesiology asks the questions:
- Who is the Church? Is it a visible or earthly corporation -- a "church" in the sense of a specific denomination or institution, for instance? Or is it the body of all believing Christians (see invisible church) regardless of their denominational differences and disunity? What is the relationship between living Christians and departed Christians (the "cloud of witnesses") -- do they (those on Earth and those in Heaven) constitute together the Church?
- Must one join a church? That is, what is the role of corporate worship in the spiritual lives of believers? Is it in fact necessary? Can salvation be found outside of formal membership in a given faith community, and what constitutes "membership?" (Baptism? Formal acceptance of a creed? Regular participation?)
- What is the authority of the Christian church? Who gets to interpret the doctrines of the Church? Is the organizational structure itself, either in a single corporate body, or generally within the range of formal church structures, an independent vehicle of revelation or of God's grace? Or is the Church's authority instead dependent on and derivative of a separate and prior divine revelation external to the organization, with individual institutions being "the Church" only to the extent that they teach this message? For example, is the Bible a written part of a wider revelation entrusted to the Church as faith community, and therefore to be interpreted within that context? Or is the Bible the revelation itself, and the Church is to be defined as a group of people who claim adherence to it?
- What does the Church do? What are the sacraments, divine ordinances, and liturgies, in the context of the Church, and are they part of the Church's mission to preach the Gospel? What is the comparative emphasis and relationship between worship service, spiritual formation, and mission, and is the Church's role to create disciples of Christ or some other function? Is the Eucharist the defining element of the rest of the sacramental system and the Church itself, or is it secondary to the act of preaching? Is the Church to be understood as the vehicle for salvation, or the salvific presence in the world, or as a community of those already "saved?"
- How should the Church be governed? What was the mission and authority of the Apostles, and is this handed down through the sacraments today? What are the proper methods of choosing clergy such as bishops and priests, and what is their role within the context of the Church? Is an ordained clergy necessary? * Who are the leaders of a church? Must there be a policy-making board of "leaders" within a church and what are the qualifications for this position, and by what process do these members become official, ordained "leaders"? Must leaders and clergy be "ordained," and is this possible only by those who have been ordained by others?
- What are the roles of 'spiritual gifts' in the life of the church?
- How does the Church's New Covenant relate to the covenants expressed in scripture with God's chosen people, the Jewish people?
- What is the ultimate destiny of the Church in Christian eschatology?
Beliefs that define the church
- Body of Christ
- Biblical canon
- Spiritual house
- Theology: beliefs about the nature of God. This can include Pneumatology (beliefs about the Holy Spirit), Christology (beliefs about Jesus being the Messiah), and Soteriology (beliefs about how people are saved).
Rituals that define the church
Topics in church government
- Apostolic succession
- Canon Law
- One Holy Catholic and Apostolic Church
- Separation of church and state
- Full communion
- Ecclesia (sociology of religion)
- Ecclesiastical polity