We see clearly from the Word that the function of the church is to be the Body of Christ (Rom. 12:5; 1 Cor. 12:12; Eph. 1:22b-23; 4:4, 16). As to its nature, the Body is universal, but as to its expression in definite places on the earth, it is local. Hence, the church has two aspects: a universal aspect and a local aspect. According to its universal aspect, the church is unique; there is only one church. However, according to its local aspect, the church is expressed in different places at different times, representing the unique universal church and functioning as the Body of Christ.
According to the New Testament, there is only one church in the universe, yet it is expressed on earth in different localities. This means that although the church is universal, its expression in this age is local. This local expression, based on the ground of locality, is the local church. Anything bigger or smaller than a locality is not fit to be the ground of the church.
The ground of the church is local and does not change according to the size of a locality. The church cannot have more than one expression in a big locality, or less than one expression in a small locality. It does not matter whether a locality is big or small, there can be only one local church within it. History tells us that in the apostles’ time, Jerusalem may have had a population of over one million and that within Jerusalem there was a large number of believers; nevertheless, there was only one church in Jerusalem. In Acts 21:20 James and all the elders told Paul, “You observe, brother, how many thousands there are among the Jews who have believed.” On ordinary days, the many saved ones met in different homes. The phrase house to house in Acts 2:46 and 5:42 denotes not a single house but many houses. This means that although the believers met in many different homes, they were not divided into many churches; rather, they were still one church. Although the Bible says that they met in many homes, it does not say that these homes were different churches within Jerusalem. On the contrary, in Acts 8:1 the Bible uses the singular word church, not churches, when speaking of the church in Jerusalem. This shows that although there were many saved ones and many meetings within the homes, there was still only one expression of the church in Jerusalem. This one expression was for the one testimony on earth, that is, that the Lord’s Body is one and has only one expression in each locality. God wants us, the believers, to keep the nature of the oneness of the Body of Christ in every locality.
The New Testament also reveals that although a certain locality may be small, it cannot be joined to other small localities to form a single church. Although there were many cities within the province of Galatia, the churches in Galatia were not joined together to become “the church in Galatia”; rather, they were spoken of as “the churches of Galatia” (Gal. 1:2). Likewise, the seven local churches in Asia were not added together to become one church. They remained seven churches (Rev. 1:4, 11-12, 20). If they had united themselves, they would have lost the nature of the church as the Body of Christ. For this reason, the church in a big locality cannot divide itself into many churches, nor can churches in smaller localities join together to form one church. We should not think that because the churches in two or three neighboring localities are small, they ought to join together to form one church. This is not permissible, because there can be only one church in each locality.
For the church to maintain its nature of oneness, it must have only one expression in each locality. The expression of each local church is a miniature, a small local representation, of the unique church in the universe, the unique Body of Christ. In other words, the local church in each locality is a miniature expression of the universal Body of Christ. This is not to say that Christ has many Bodies on the earth; rather, this is to say that Christ has many miniature, or small-scale, expressions and that each small-scale expression is a representation of the unique large-scale Body in the universe. The Bible says that the church is the Body of Christ. Universally it is one, but it is expressed in numerous localities. The Body of Christ in Ephesians 1:22-23 is spoken of in reference to the church in its universal aspect, whereas the Body in Romans 12:5 and 1 Corinthians 12:12 is spoken of mainly in reference to the church in its local aspect.