In one respect, a search through the New Testament may result in a myriad of things that believers should do. Speaking generally, and keeping the conversation to the dispensational distinctives, one could propose three primary responsibilities of the Church in the governance of the affairs of mankind. If the Church fulfilled these three responsibilities, it would certainly result in the Church having an effect on the world around it.
First, in Acts 1:8 the Church will be a witness to Jesus Christ. The disciples were looking for the Kingdom, and they asked Jesus if, now that he had been resurrected from the dead, he would restore the Kingdom. Jesus responds by telling his disciples not to worry about when the Kingdom will be established; that is God’s responsibility. In the meanwhile, whatever is going to happen, the disciples are to bear witness of Jesus Christ in all the world. It is the business of the Church to spread the gospel around the world.
Second, in Ephesians 4, the Church is to teach truth. Paul instructs the church in Ephesus that God has given men to the churches in order to instruct the churches so that “we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ, so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine, by human cunning, by craftiness in deceitful schemes.”
God has certain expectations of local churches. A church is to grow in Christ, to mature like a grown up. If a church stays as a child, then false doctrine can sneak into the church and destroy the church. Therefore, God gave leaders, pastors and teachers, to teach the people so that they can mature in their understanding of doctrine and knowledge of Jesus Christ.
Third, believers are to live in a manner worthy of the Gospel according to Philippians 1. Doctrine is important according to the passage in Ephesians 4. How a believer conducts his life is equally important. The Christian life is more than just giving mental assent to a doctrinal statement. The life of the believer is directly tied to the Gospel of Christ. If a believer does not live in a manner worthy of the Gospel, his testimony of Christ is tarnished, as is the unity of the church.
Most dispensationalists agree that the Church began on the day of Pentecost as recorded in Acts 2. According to Paul in Ephesians 1, the Church is a mystery that was not revealed in the Old Testament. In Matthew 16, Jesus refered to the building of the Church as something yet future. Paul states that the foundation of the Church is the death and resurrection of Christ. Thus, it could not start until after his resurrection.
In Acts 2, Luke describes the coming of the Holy Spirit and Pentecost. The Jews spoke in tongues as they preached the Gospel in Jerusalem, while thousands of people believed and were saved. In Acts 10, Peter goes to Cornelius’s house, the house of a Gentile. As he is preaching, the Gentiles believe the Gospel, are saved, and then they begin to speak in tongues. The speaking in tongues, Peter says, is evidence that whatever happened to the Jews on the day of Pentecost has happened to the Gentiles. He refers to Pentecost as “the beginning.”