The churches of Asia send you greetings. Aquila and Prisca, together with the church in their house, send you hearty greetings in the Lord.  All the brothers send you greetings. Greet one another with a holy kiss.
The churches of the first century were united with each other. They did not consider themselves to be independent congregations all doing their own thing. They were united together through faith in Christ, and therefore purpose. The cause of one was the cause of all. They shared leaders in the apostles, and those the apostles left in charge. To many today want to forsake this unity for a supposedly nondenominational church. This is wrong, we are not independent of each other. Denominations can go wrong. They can also be a great blessing to the church as a whole and to independent congregations. They facilitate the work of the Lord bonding the individual congregations, to help with mission work, the training of faithful pastors, charity work, etc. Together they can do more than they can apart. If congregations are in agreement in doctrine, and unified in Christ, it is proper that that is given formal recognition in the form of a denomination. To do otherwise is to be sectarian, and arrogant. The Church in Corinth is a good indication of where such arrogance leads, when you think you and your congregation is all there is to “Church.” Paul takes them to task for this when he says:
 Or was it from you that the word of God came? Or are you the only ones it has reached? 1 Cor. 14:36 (ESV)
We do well to remember our brothers and sisters in the faith in other congregations, and not improvise practices in our church that will be offensive without cause to those of the other congregations who wish to remain faithful to God’s word. We do well to strive for unity in the same judgment and mind, not only within individual congregations, but between congregations also.