“An assembly is a company of baptized believers (Acts 2:41), gathered unto the Name of the Lord Jesus Christ (Matt. 18:20; 1 Cor. 1:1-9;5:4 etc.), who meet regularly in a particular locality according to the pattern found in the [New Testament] in Acts 2:41,42, and developed fully in such epistles as 1 Corinthians and 1 Timothy. Such an assembly is a spiritual fellowship (1 Cor. 10:16,17), which is expressed visibly as they meet for the breaking of bread, prayer, collective testimony, the teaching of the Word of God and the preaching of the gospel.
They have been gathered together by the Holy Spirit (Mark 14:13; Rom. 8:14), their sole authority is the Word of God (2 Tim. 3:16,17), and they have the promise of the Lord Jesus Christ to be in their midst (Matt. 18:20). They are a residence of the Holy Spirit on earth, so they are a holy temple unto the Lord (1 Cor. 3:15,16).
Such an assembly is guided by godly overseers and served by faithful deacons in both a temporal and spiritual ministry (1 Tim. 3:1-16). The priesthood of all believers is exercised in worship, praise and prayer, and the gifts, given by the risen Head of the church (Eph. 4:8-13) have the liberty to function under the control of the Holy Spirit (1 Cor. 14:23-40).
There is a clear demarcation between the within and the without of an assembly and purity is maintained by careful, compassionate and godly exercise of discipline (1 Cor. 5:1-13).
This is a carefully written statement, but claims no authority for itself. It is only the Word of God that has authority in the realm of testimony for God.”
Crawford, Norman., Gathering Unto His Name. Glasgow: Gospel Tract Publications., 2003, p. 30