The first time the church is mentioned in Scripture is in Matthew 16 where, in response to Peter's confession of the Lord, He answered, "Upon this rock I will build My church." The building began at Pentecost, and has continued ever since, and every one that has believed the gospel of our salvation, has been sealed by the Holy Ghost and added to that indestructible structure, the one church, which is the body of Christ. As the work spread out from Jerusalem to other centres, and churches were established in every city to which the gospel was carried, the bounds of the one church were extended, and of course those who believed could no longer all come together in one place, yet they did not come together in their own localities as being separate or independent churches, but as being one with those who were in Christ before them. The separation was purely geographical, and not of the heart, mind, purpose, or doctrine; the truth that there is one body and one Spirit and one hope of your calling, remained the same.
The church is not made up of a federation of local churches, but each church is a local expression of the one church, hence the churches are not a number of independent bodies but are part of an indivisible whole, and their constitution and character should be moulded and governed by the truth of the whole church. Christ is the one and only Head and Director of the church, which is His body; and the Holy Ghost who dwells in each member of the body and in the church as a whole, is the medium and power by which His mind is made known to us and carried out, as it is revealed in the Scriptures.
If the churches had always been subject to Christ as the Head of the church, and their Lord in their local responsibility, all would have moved on together and the oneness of the church would have been a visible thing. It is here where the widespread failure has come in. The responsibility to be faithful to Christ as His witnesses, wherever they are, rests with the local churches, as Revelation 2 and 3 shows, and while the spiritual intelligence and circumstances may not be the same in any two churches, and this is not overlooked by the Lord in His scrutiny of them, yet His word to each one is for all, and His commandments (1 Cor. 14:37) are for all that in every place call upon the Name of Jesus Christ our Lord (chap. 1:2). To set up other heads, or to formulate rules and regulations and conditions of fellowship and membership not found in these commandments of the Lord, is a challenge to His authority and an ignoring of the presence of the Holy Spirit in the church and a denial of the sufficiency of the Scriptures.
No company of Christians in any place can rightly claim to be the church of God in that place unless it includes all the Christians in it. Yet it is possible for even "two or three" to meet together according to the whole truth as to Christ and His church, and to walk in it. This would involve the exclusion of evil as indicated in the Word and the recognition and reception of all who carry Scriptural qualifications for fellowship.