Scripture clearly supports the view that believers should be identified with an organised local assembly of christians.
The Nature of a New Testament Church
A readiness to accept the biblical doctrine of the Church will inevitably include acceptance of the principle of church membership. The use of the word church in the New Testament indicates that the early christians were not only incorporated into the One Body of Christ (the Universal Church) but also joined themselves to a local assembly (the local church). Compare 1 Cor. 12:13 with 2 Cor. 8:4. Here they covenanted together in a bond of fellowship with other believers, thus entering a particular visible society with a distinct and restricted membership. Scripture gives no grounds for a believer belonging to the Universal Church while abstaining from local church membership.
2 Cor. 8:4; Acts 2:41 ff.; 8:1; 11:26.
The Need for Organisation within a local church
The New Testament makes clear that the apostolic churches were organised. They dealt with matters of discipline, and appointed church officers. The words of Acts 6:3 — “look you out from among you seven men of honest report” — presuppose that the original Jerusalem church was an organised body of converted people. The apostolic churches were disciplined, organised bodies with clearly defined memberships.
1 Tim. 3:15; Titus 1:5; 1 Car. 14:33, 40; Mat. 18:15-20; Acts 6: 1-6; 13:1-4; 1 Cor. 5:1, 2.