In the Bible, the Greek word translated as “church” means an assembly or gathering of people who believe in the good news about Christ Jesus. They have been shown God's purpose and have been chosen to do God's will in the world. The church belongs to Jesus the Lord, who is its “head” (Eph 1.22; Col 1.18). The Greek word for Lord is kyrios, so the church is also called kyriakon, which means “belonging to the Lord.” Kyriakon is the basis of the English word “church.”

The church is pictured in various ways in the New Testament. It is the obedient people of God in Matthew. Paul argues in Romans and Galatians that the church is a new people, and not the same as the chosen people of God who, in the Jewish Scriptures, were required to obey the Law of Moses. He also refers to the church as the “body of Christ” (1 Cor 1.12, 27-31). In Luke and Acts, the most important work of the followers of Christ is to reach out to the whole world (Acts 1.8), regardless of race or culture. In Acts, the church is described as those who follow “the Lord’s Way” (Acts 9:2; 24:14); and the author of Acts notes that it was in Antioch in Syria that Jesus’ followers first were called “Christians” (Acts 11:26). The writer of 1 Peter describes the people who make up the church as “God's chosen and special people” and “a group of royal priests and a holy nation” (1 Pet 2.9; see also Exod 19.5,6). In John the church is described as the flock belonging to the Good Shepherd (John 10.16) and as branches of Jesus, the true vine (John 15.1-16).

After the first generation of the apostles was gone, the church gradually became more structured in its organization, with clear leadership roles and rules for the behavior of its members clearly defined. Descriptions of this organization first appear in letters like Ephesians, 1 and 2 Timothy, and Titus, and in the writings of second century church leaders known as the Apostolic Fathers. It was then that leaders called in Greek episkopoi (sometimes translated “bishops”) were appointed to oversee the work of the churches.