The word church is used in three ways in the New Testament in reference to the blood-bought institution of the Lord.
First, the word church refers to the body of Christ as a whole or the universal church. This is the meaning when Jesus said “upon this rock I will build my church” (Matt. 16:18).
Second, it can refer to a congregation of that universal body—a local church or congregation. This is the meaning of “the church of God which is at Corinth” (I Cor. 1:2) and “the seven churches which are in Asia” (Rev. 1:4). It is this sense of the word which gives identity to congregations and makes their autonomy possible.
The third and perhaps least understood meaning of the word church is a congregational assembly for worship. In I Corinthians 11:18 Paul said, “when ye come together in the church” which means the congregation came together as an assembly to worship. It is used throughout I Corinthians 14 in the same sense.
The word church is from the Greek word ekklesia. This word was used outside the Bible to mean “a gathering of citizens called out from their homes into some public place; an assembly” (Thayer, Greek-English Lexicon, pp. 195-196). Sometimes in the New Testament an ekklesia is a gathering that has nothing to do with worship. This is how it is used of a crowd or “assembly” of people at Ephesus (Acts 19:32,41). The assembly of Israelites in the Old Testament is called an ekklesia or church in Hebrews 2:12. Applied to the body of Christ an ekklesia is the congregational assembly for worship in passages like I Corinthians 11:18 and I Corinthians 14:23.
A similar case is the Greek word synagoge which is the word for synagogue. It means a building in passages like Luke 7:5. But it can also mean the assembly of people in that building. In Acts 13:43 “the congregation was broken up.” This congregation was a synagoge. This is the same word that is used in James 2:2 to refer to an “assembly” of Christians for worship.
With these thoughts in mind consider the emphasis placed on the assembly for worship in the New Testament:
Acts 20:7 – “And upon the first day of the week, when the disciples came together to break bread…”
I Corinthians 11:17 – “…ye come together not for the better, but for the worse.”
I Corinthians 11:18- “…When ye come together in the church.”
I Corinthians 11:20 – “When ye come together therefore into one place…”
I Corinthians 11:33-34 – “Wherefore, my brethren, when ye come together to eat, tarry one for another…that ye come not together unto condemnation.”
I Corinthians 14:23 – “If therefore the whole church be come together into one place…”
I Corinthians 14:26 “How is it then, brethren, when ye come together…”
Hebrews 10:25 – “Not forsaking the assembling of ourselves together…”
James 2:2 – “For if there come unto your assembly…”
Weigh these words carefully. The church is not a building, but a congregation is to assemble in some place. The central idea of a congregation is that it congregates. Segregation is not a congregation.