Does “doing all the right things” make a group of believers an assembly?
No. The title used in the New Testament for an assembly is “church of God.” This indicates both the ownership and origin of an assembly. It originates with a divine work. Only God can save souls, but the existence of a number of believers doesn’t constitute an assembly. In Athens, we have no indication of the planting of an assembly, although a number there were saved (Acts 17:34). In the “pattern assembly” at Jerusalem, “they that gladly received His word” were baptized and added to “the fellowship” (Acts 2:41, 42). This willingness to receive the truth of God is essential in the planting of an assembly, because believers are to “continue steadfastly in the apostles’ doctrine.” How will these new believers know how to function as an assembly without being taught?
More than that, if the Lord is working to plant an assembly, we would expect some indication that He is raising up a plurality of men with shepherd hearts (Acts 20:28). Novices are not yet fitted for that work (1 Tim 3:6); however, when God is forming an assembly, we would expect some among these new believers to display a potential for that work.
The Lord Jesus explained His use of the word “church” (Mat 18:17) by saying, “Where two or three are gathered together in My name . . .” (v 20). Those gathered did not gather themselves, but are drawn to “the name” by another agent, evidently the Spirit of God. This is related to the Old Testament expression, “the place which the Lord shall choose to place His name there” (Deu 16:2). The Lord establishes the testimony (places His name) and believers are drawn to what He has established.
“Doing all the right things” will never make a company an assembly if the Lord has not first of all made it an assembly.
Is it still an assembly when the believers do all the right things, but don’t have love?
How much better if no assembly ever gave reason for such a question to be asked!
To be fair, not everyone expresses his love in the same way. Sometimes a believer perceives a lack of love in others because he expects others to express love in the same way he does.
To be honest, a lack of expressing love in an assembly is not a deciding factor in whether it continues to be an assembly. Believers must love one another or they are not demonstrating that they have divine life (1Jo 3:14). The absence of expressing love for one another is an evidence that the Spirit is grieved in that believer (Eph 4:30; Gal 5:22). When the Spirit is grieved, what is to hinder that assembly from losing its devotion to Christ and subsequently its lampstand (Rev 2:4-5)?
What practices are necessary for a group of believers to become an assembly, and what causes it to cease to be an assembly?
Those who study artist’s work recognize the work of famous painters. Even apart from his name on the painting, each artist’s work has his unique “signature” in its details. And so it is with God. If He has established an assembly, it will bear God’s “signature.” This signature is the design which is always consistent with the pattern given in His word. God doesn’t need variety to somehow amuse Himself. He works consistently and follows the same pattern He gave nearly 2000 years ago. Here are some things we would expect: no other name but the Lord’s to identify the group; a plurality of overseers; separation from denominational associations; the display of head coverings as taught in 1 Corinthians 11; evidence of the priesthood of all believers; attention to the development of gift; supremacy of the Word of God; gatherings for at least the breaking of bread, prayer, ministry, and gospel; recognition of the different roles God has entrusted to males and females; the practice of both baptism for all believers and also biblical reception.
When the Lord removes a lampstand (Rev 2:5; 3:3, 16), of course that group ceases to be an assembly. When He does that, only He knows. The group may continue its activities – and perhaps do all the right things, as the church at Ephesus did – yet not be an assembly.
How could the Lord acknowledge an assembly when it had departed so far (Revelation 2 and 3)?
The assembly at Corinth was badly damaged by the influence of the world around it. Galatian believers had been influenced by serious doctrinal error. These and other assemblies, including those in Revelation 2 and 3, began as assemblies, through God’s work, consistent with the pattern. The Lord determines how far an assembly can depart. He reads the heart and judges righteously. We are not responsible to make that decision. He requests permission of no one and informs no one.
We are responsible, though, to preserve the integrity of the assembly of which we form a part. Whether or not a certain company is an assembly, if its practices and associations will damage young believers or lead any astray, we shouldn’t associate ourselves with that assembly.
Does Matthew 18:20 apply only to “our assemblies”?
That is looking at the truth backwards. In this passage, the Lord informs us that a church (v 17) is His dwelling place (v 20). As such, He gives it authority to administer His wishes (v 18). So it is the Lord Who determines which group is His dwelling place. This truth doesn’t belong to “us.” It is God’s universal truth. Some may “claim” the verse, but that doesn’t make them an assembly.
We learn from this passage some of the privileges and responsibilities of an assembly. Wherever God has worked and planted assemblies, they do not become “part of us.” They are the Lord’s, purchased with “the blood of His Own.” Wherever He has gathered believers to His name, they are His dwelling place and act with His authority. We do not have a monopoly on this truth, but it should be clear that any groups to which this applies will be building according to the same pattern we are seeking to follow.