My "Church" Membership
I am not a member of a denomination called "Church of Christ" or "Churches of Christ" or a denomination with any other name. The local church where I regularly attend is not a congregation of the "Church of Christ" denomination.
Yet, I have been a member of the church of Christ (AKA "church of God" or "church of the firstborn") for over 60 years. I became a member when I became one the number of the saved. The Bible tells us, in Acts 2:47, that "the Lord added to the church daily those who were being saved"(NKJ) or "the Lord was adding to their number day by day those who were being saved" (NAS). This "church" is that number of those who have been saved by the Lord. They are the same as those that have been "added to the Lord" (Acts 5:14; 11:24) and those who have been "baptized into Christ" (Galatians 3:17) or "baptized into one body" (I Corinthians 12:13). We sometimes call this the "universal church." It has no "organization" as we commonly use that term. It is simply individuals working under the headship of Christ. The only functioning unit is the individual Christian. It is not "organized" at any level – global, national, state, or area. Nor is it an organized enmity with organized subdivisions. Again, it is simply the saved – those whose names are written in the Book of Life (Philippians 4:3; Revelation 21:27). There is no earthly census to number how many make up this body, only God knows the number. Thus, only God accepts people into that number and only God can remove one from that number (Revelation 3:5).
Also, over the years I have been a member of various organized units made up of those, from the community where I lived at the time, who were among that great number of the saved (as far as we can humanly tell) and who have agreed to worship and work together as a unit according to the authority of Christ. The unit that I am now a member is the "church of Christ at Kimberly" or "Kimberly church of Christ."
Organized units like these are designated plurally by such terms as "churches of Christ" (Romans 16:16), or singularly as "the church of God at Corinth" (I Corinthians 1:2; II Corinthians 2:1) and other such terms that magnify God and his Son. They are not a subdivision of some larger unit. They are never referred to as a "congregation of the Church of Christ." (That would be like say, "a church of the Church of Christ"). When fully organized, they appointed a plurality of qualified men as elders from men among them (Acts 14:23; I Peter 5:1-4). They were not organically tied to each other in any way. They were governmentally or organizationally autonomous units. While not tied together organically, they had a common interest and common authority. (I Corinthians 4:17; 7:17). Because of this common interest and authority, they sometimes cooperated with each other, while maintaining their organizational independence. They sometimes sent relief to other like local churches to help them provide for the needy among them (Acts 11:27-30; I Corinthians 16:1-4; II Corinthians chapters 8 and 9). Various ones of them sent wages to a preacher as he worked in other areas (II Corinthians 11:8; Philippians 4:15-18). Each of these local churches has the right and responsibility to receive (Acts 9:26; Romans 14:1) and expel (I Corinthians 5:1-13) its members according to the teaching of the Lord through the apostles. Being administered by humans, mistakes are sometimes made in this process. Sometimes these churches receive and harbor those they should not (I Corinthians 5). Sometimes they expel those they should not (III John 9-10). When this happens it should be corrected (I Corinthians 5:1-6).