III. As Revealed by the Apostles in Acts and the Epistles
C. Each Being Not Greater nor Smaller Than Its City
Below, Witness Lee explains in greater depth the jurisdiction and boundary of the local church:
A local church should not be greater nor smaller than its city. This means that the jurisdiction of a local church should cover the whole city in which the church is; it should not be greater or lesser than the boundary of the city. All the believers within that boundary should constitute the one unique local church within that city. Hence, one church equals one city, and one city equals one church. This is what we call the local churches.
In every place there can be only one expression of the church. The expression of the church cannot be greater than a locality, nor can it be smaller than a locality. Furthermore, the churches in a number of places cannot be combined to form an alliance of churches, and the church in one place cannot be divided into a number of churches on certain streets, roads, or lanes, or in certain neighborhoods. There can only be one church in one locality. (2154-2155)
Witness Lees definition of the jurisdiction and boundary of the local church clarifies why there can only be one church in one city.