The parting words of our Lord Jesus Christ to his disciples are as follows: "All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptising them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age." (Matthew 18-20)
Through the preaching of the gospel the apostles made disciples and these disciples of Christ became the church of Christ. We can read about this in the Acts of the Apostles. And what was true for them is true for us today – wherever the gospel is preached and obeyed the church comes into existence there.
The gospel proclamation is that God has provided a saviour in Jesus Christ whose death upon the cross has paid in full our penalty for sin and set us free from sin guilt. His victorious resurrection gives us "a living hope". (1 Peter 1:3) The message of the resurrection is what Jesus charged his disciples to proclaim throughout the world.
The Church Comes Into Existence
On Pentecost the Holy Spirit came upon the disciples, empowering them for the work the Lord had called them to do. Peter proclaimed the gospel and the Spirit brought conviction to the hearts of those who heard. "They said to Peter and the other apostles, 'Brothers, what shall we do?' Peter replied, 'Repent and be baptised, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit … Those who accepted his message were baptised, and about three thousand were added to their number that day." (Acts 2:37-41) In the days following, the gospel continued to be proclaimed and more and more people were believing and being baptised. "'And the Lord added to their number daily those who were being saved." (Acts 2:47)
The thousands who were responding to the gospel were being saved by the Lord and were the first members of his church. The church is the saved.
The Church Begins At Philippi
Arriving in the city of Philippi, Paul and his companions found a group of people who had gathered for prayer. "We sat down and began to speak to the women who had gathered there. One of those listening was a woman named Lydia, a dealer in purple cloth from the city of Thyatira, who was a worshipper of God. The Lord opened her heart to respond to Paul's message. When she and the members of her household were baptised, she invited us to her home. 'If you consider me a believer in the Lord,' she said, 'come and stay at my house.' And she persuaded us." (Acts 16:13-15)
When these people believed the gospel they were immediately baptised and counted among the people of God. They, like those on Pentecost, were part of the church Jesus had come to establish.
The Church Begins At Corinth
Within Corinth, a notoriously sinful city, a community of light was about to be established. "The Lord spoke to Paul in a vision and said, 'Do not be afraid; keep on speaking, do not be silent. For I am with you, and no one is going to attack and harm you, because I have many people in this city.' So Paul stayed for a year and a half, teaching them the word of God." (Acts 18:9-11)
Paul preached the gospel and as a result, "many of the Corinthians who heard him, believed and were baptised." (Acts 18:8) Some years later, Paul wrote and addressed them as "the church of God in Corinth". (1 Corinthians 1:2)
Establishing the Church Today
Though the church came into existence 2,000 years ago through the preaching of the gospel, it still needs to come into existence in many parts of our world today since so much of the world remains unevangelised. Even so-called "Christian Europe" is in urgent need of evangelisation.
Whenever a person is converted to the Lord Jesus Christ - redeemed, forgiven, saved, born again - that person becomes a member of the church Jesus came to build. For the church of Christ is simply those whom he has saved. They are those who have been called by God to be his people, his body in the world.