There really is no Biblical warrant for faithful believers living together in the same community but refusing to worship together or to have anything to do with each other.
I'm not sure I'm following you.
1Cor.1
[2] Unto the church of God which is at Corinth
2Thes.1
[1] Paul, and Silvanus, and Timotheus, unto the church of the Thessalonians
Acts.11
[22] Then tidings of these things came unto the ears of the church which was in Jerusalem
Does the use of the word church in these passages indicate that there were many churches in Corinth, Thessalonia and Jerusalem?
Acts.9
[31] Then had the churches rest throughout all Judaea and Galilee and Samaria
Acts.15
[41] And he went through Syria and Cilicia, confirming the churches.
1Cor.16
[1] Now concerning the collection for the saints, as I have given order to the churches of Galatia
Does the use of the word churches in these passages mean there were many churches in Judea, Galilee, Samaria, Syria, Cilicia and Galatia?