It Isn't In The Book
The popular idea In religion today is that "one church is as good as another" therefore everyone "should join the church of his choice". That leaves the Church that Jesus built, designed by the God of heaven and dwelt in by the Holy Spirit on a level with religious institutions that men have designed and built with no superiority at all over them. It also leaves out God in the matter of "choosing what church we should join". Does God have the right to a choice as to what we shall be in religion? One would think so but a lot of people do not seem to consider it that way.
Where in the Bible do we read of Churches? All of us who have read our Bibles any at all know that "churches" of different kinds or order are not found in the Bible. Congregations of the same faith and order like the "seven churches of Asia" or the "Churches of Christ" that sent greetings to the Church in Rome through Paul in his letter are found in the Word of God but these were all planted by the same Gospel, had the same faith, had obeyed the same commandments, worshipped God in the observance of the same ordinances, carried on the same work, and were organized in the same manner exactly. They were "churches" in the sense that they were different congregations of the same faith and order located in different localities.
Jesus said, "I will build my church". Matt 16:18. Paul wrote to the "Church of God" which is at Corinth. People who heard the Gospel, believed and obeyed it were added to "the church" — not to churches. When the great meeting on Pentecost had concluded, they did not take all those who had been converted aside and let them "join the church" of their choice. Rather God added them to the Church of His choice. Acts 2:21, 2:47.
Not only is it impossible to find different kinds of churches in the Word of God but it is also impossible to read of anyone who "joined" the Church of the Lord. Men cannot "join" the Church that Jesus built. They must be added to it and God does the adding.
The church of the Lord is the family of God. It is God's household. 1 Tim. 3:15. Eph. 2:13-22. When we are born again we are children of God, members of God's family and therefore in God's household or God's Church. It is that simple.
The same process that saves one, puts him into Christ, and adds him to the body of Christ, the Church. Look at three passages on the point and compare them.
Mark. 16:15-16. Believe and be baptized — shall be saved.
Gal. 3:26-27. Faith and baptism — in Christ — put on Christ.
Acts 2:41-47. Receive the Word and be baptized — Added — added daily to the church — the saved.
Contrary to the denominational idea, one is not born again, saved, by one process and made a member of the Lord's Church by another.
All of this means that because the Bible does not contain the idea of many churches and says not one word about "joining" any church, these are false notions for which God is not responsible. They belong to the doctrines and commandments of men and are therefore wrong. They are not in The Book!