To most, it seems presumptuous for one church to claim to be superior over all other churches and self-righteous for it to teach that one must be a member of that group to be saved. Many are offended because they misunderstand what members of the church of Christ teach, and perhaps, because it is sometimes taught in the wrong manner. I do not want to be arrogant or rude, but plain and truthful in stating my convictions about what the Bible teaches concerning the church and salvation. I do not believe one is saved simply because he worships at a place where the words "Church of Christ" appear on the building or on a sign in front of the building, but neither do I believe that "joining the church of your choice" is right! Indeed, one who is saved is a member of the church that Jesus built- the church that belongs to Him, His church- "the church of Christ."
The church was a part of God's eternal plan (Ephesians 3:10,11). Christ promised He would build the church (Matthew 16:18), and did so by purchasing it with His blood (Acts 20:28). This church is sometimes referred to as His body (Ephesians 1:22,23), and Jesus is its head (Ephesians 1:22,23). Furthermore, God purposed only one church, Jesus built only one church, and only one church belongs to Christ and God (Ephesians 4:4). This one body of Divine origin is rightfully called the church of Christ since it belongs to Christ. The Bible also refers to this group of the saved as the church of God (Acts 20:28), the church of the Lord (Acts 20:28, ASV), and other such designations (Hebrews 12:23) that give honor and glory to God and to Christ, its founder and Savior.
Jesus built the church when He shed His blood on the cross and sinners obeyed the gospel on the Pentecost after His resurrection (Acts 2:47). The Lord adds those who are saved to the church (Acts 2:47). The church does not save us; the church is the saved! The church is not our Savior, but Christ is the Savior of the body, the church (Ephesians 5:23). You cannot separate the saved from the church nor the church from the saved; they are one and the same. Hence, anyone who is saved is a member of the church that belongs to God and Christ.
The church that you read about in the New Testament to which the saved are added is not made up of denominations. It is not a church of churches. People are not saved by joining denominations; neither are the saved added to denominations. Denominations were started by men, not by Christ, and they exist because each group teaches some peculiar doctrine or wears some name distinguishing them from all others. But all members of the church that belongs to Christ have obeyed the same gospel commands to be saved- they have all heard the gospel (Romans 1:16; 10:17), believed Jesus to be the Christ (John 8:24), repented of their sins (Acts 17:30), confessed Jesus as Lord (Romans 10:9,10), and been baptized for the remission of sins (Mark 16:16; 1 Peter 3:21); they are all called Christians (Acts 11:26), and all are to contend for the one faith (Ephesians 4:4; Jude 1:3). Denominationalism promotes division, but Christ pleads for unity (John 17:20,21; 1 Corinthians 1:10-13; Ephesians 4:3-6). Denominations are not the church of Christ, or church of God, that you read about in the New Testament. One cannot "join the church of his choice" and be saved. One must obey Christ's gospel to be saved and to be a part of Christ's church. One church is not as good as another; the Lord's church is the right church!
If Christ built and purchased His church, and everyone who is saved is added to that church by the Lord, then only members of the church of Christ are saved. Membership in the church is not the means of salvation; it is the result of being saved. People worshipping in a building with the words "Church of Christ" on the front of it or on a sign out front may or may not be the church that belongs to Jesus. The sign has a name that honors and glorifies God, but have the people been saved the way the Lord directs and do they teach and practice the gospel? Many do, and perhaps, a place with such a sign out front is a good place to begin to look for the church. One should not be offended by the phrase "Church of Christ" when used scripturally.
It is not presumptuous to teach what one believes to be the truth about the church and salvation. Nor is one being self-righteous who seeks to be saved through Jesus and to be added to His church rather than to a denomination. I share this doctrine with you, not to condemn you, nor to force you to accept an opinion, but that you might "search the scriptures " to see if it is true (Acts 17:11). It matters what we believe and practice (1 Timothy 4:16).
"Every plant, which my Father hath not planted, shall be rooted up"