Church, the basic organization of Christianity, can refer to the whole organization of various Christian sects, such as the Christian Church, the Catholic Church, the Orthodox Church, etc., and can also refer to the organization of all Christians in a country, a region or a church, such as the Church of England, the Church of Jerusalem, the Church of a certain church, etc.
The term "Christian Church" or "Grand Ducal Church" can be traced back to the customary address of Christians to Christianity in the second century AD. The word church has the same meaning as the Christian church (that is, "the body of Christ"), but the word church has a broader meaning. In the traditional Christian church, the word is used to refer to the congregation (this is the original meaning in Greek, which is ε κκ κ λ ησ I α). The term "Christian Church" can also be interpreted as a specific Christian sect, such as the Christian Church, the Independent Christian Church and the North American Christian Church. The early church was a community of all believers. Believers met and worshipped regularly in different places, and were governed by supervisors, elders and deacons. With the improvement of the church's organizational form, the church has become an organization with bishops and other teaching staff as the core. After the great division in 1054 AD, Catholicism still maintained its status as an orthodox church in Western Europe. It was not until the religious reform in the sixteenth century (from 1517) that it lost its position as the only church in Europe. The Eastern Orthodox Church and Catholicism also claim the same orthodox status. Until now, the term church is still commonly used to refer to the Eastern Orthodox Church.
In the 3rd century AD, Clement and Origen of Alexander put forward the idea of visible church and invisible church. The former refers to the organized church in the world, while the latter refers to the eternal church in heaven. The church in later generations has a broad meaning. It can refer to the entire organization of various Christian sects, such as the Catholic Church, the Eastern Orthodox Church, the Protestant Church, or the organization of all Christians in a certain country, region or church. The church in China mainly refers to the Protestant church. In the 4th century AD, Christian theologian Augustine proposed that the church is the tangible embodiment of the city of God in the world, but the real church is invisible and only exists in the mind of God. However, many believers believe that the establishment of a visible unified church in the world is in line with Jesus' will. Since the beginning of the 20th century, European and American Protestants have launched the universal church movement, also known as the church unity movement, whose main purpose is to restore the unity of the Christian church.
