The work of the Holy Spirit:
As we have just celebrated the Feast of Pentecost, let us examine the one more function of the Holy Spirit within the Lord's Congregations.

The spirit creates unity. One of the notable ways in which the Spirit expressed Himself in the church or assemblies was through creating unity. In (Eph 4:3-4), Paul says, ‘there is one body, and one Spirit’. Here he is telling us that like so much in the spiritual life, unity is a gift of God, and yet we have to work at it. Our sinful nature will devise ways that will appear to 'unite' Congregations together, but in reality will cause division! This is evident all around us if we are willing to see it.

In each local assembly which is indwelt by one Spirit, there is no place for distinctions of wealth or station, sex or nationality; no room for pride in education or religious privilege. (Col 3:11) where there is neither Greek nor Jew, circumcision nor uncircumcision, Barbarian, Scythian, bond nor free: but Christ (Messiah) is all and in all. In Jas 2:1, James tells us that if we have the faith of Christ (Messiah), we should not show partiality when dealing with people.  After all, not one of the apostles had any wealth to boast about! Even we do not have anything we can call our own.

The Congregations must preserve Unity.

This concern to 'preserve unity' is something the Spirit had created, and accounts for so much in the life and teaching of the Lord's early congregations. It was this desire to create 'unity' by using the wisdom of man that the church was divided into different denominations.

It was this spirit of unity that made the council at Jerusalem advise that there should be not be any  independent churches growing up separately from the mother congregation in Jerusalem. It was this spirit of unity that made the council of Jerusalem to decide that the issue of circumcision must not be allowed to split the early congregations (Acts 15). It was to preserve this unity that the Apostles visited the Gentiles so frequently (Acts 8:21; 20:16; 25:1), and Paul organized of a great collection for their benefit.

John also says, "You all have knowledge . . . you do not need anyone to teach you" (I Jn. 2:20, 27). This 'unity' in the Spirit bridges the gap between Jews and Gentiles once they become members of the Congregation (Eph 2:15) and breaks down the hostility between men of different colors and backgrounds.

Unity at Antioch -There is a splendid example of this in the Congregation at Antioch (13:1 A.). Its leadership was corporate, unlike that of most modern congregations; it was made up of prophets and teachers in the leadership together. Barnabas was a rich, land-owning Cypriot Levite. Simeon, who seems to have been an African, Lucius Of Cyrene, a Jew from North Africa, Manaen, who was educated in court circles alongside Herod the tetrarch; and Saul of Tarsus, the Jew who had studied under Gamaliel. Messiah’s desire that ‘they all may be one’ (John.17:21) was fulfilled in that early church at Antioch.

The Spirit Brings Reconciliation.
Another work of the Holy Spirit is that of reconciliation. It is well brought out in (Eph 2:14, 18). A great wall separated Jews from Gentiles in the ancient world: the law. This was symbolized by the notice in the outer court of the temple threatening death to any Gentile who went beyond that point.
The 'unclean' could not enter the sanctuary of the Lord. The Jews despised and hated Gentiles: because they did not belong to the elect; and hated them because the Gentiles were in authority over the Jews. But Messiah broke down that barrier. The gospel and salvation are for both Jew and Gentile. Both have been reconciled in one body by Messiah. 

The Spirit brings down all walls. The Spirit reconciles men who at not of the same mind. This is a characteristic of the work of the Spirit in the church and is hindered only by man walking in his own wisdom and ingenuity. If you want to have that unity with your brethren, you should be of the same mind (2Cor.13:11), speak the same thing (1Cor.1:10), believe in only one gospel (Gal.1:6-10) and do not believe in too many doctrines (Eph.4:14)
Because the Holy Spirit dwells in the congregation of Messiah, it produces fellowship. Where there is no indwelling of the Holy Spirit, there can be no unity nor fellowship.

Christ calls us into His church through the gospel. Therefore, we can begin by obeying the same instructions that Peter gave on the Day of Pentecost (Acts.2:38), by repenting of our sins, and being baptized for the remission of our sins.

The early Christians continued steadfastly in the apostles' doctrine - Ac 2:42.They did not join any other religious organization. By being in Christ, we are automatically united with all others who are in Him! As members of the Lord's church, we should study carefully the New Testament description of the church that continued steadfastly in the apostles' doctrine. It is here that we will find instruction from the Lord's apostles on how to be scripturally organized as local congregations and live and work together as Christians, spreading the gospel of Christ through word and example. Since the apostles were guided by the Holy Spirit, we may be sure their instructions were exactly what Jesus wanted them to be!