The beginnings of the Christian church are recorded in the Book of Acts. The church is defined by the commission Jesus gave them, and empowered by the Holy Spirit who guides them.
The Book of Acts
The four gospels at the beginning of the New Testament tell about the ministry of Jesus during his time on earth, from his birth to his resurrection. The history continues in Acts, which reports the beginnings of the Christian church. Acts spans a period of 30 years, from Jesus’ resurrection to Paul’s imprisonment in Rome, as he awaits trial in the court of the Emperor.
Acts is really the sequel to the gospel of Luke. This is clear from the very first verse:
In the first book, O Theophilus, I have dealt with all that Jesus began to do and teach, until the day when he was taken up, … (Acts 1:1, ESV)
The “first book” is the gospel of Luke. Many of the themes of Luke continue. The work that Jesus began continues through his apostles. Through their travels and preaching, Jesus’ message of the Kingdom spreads through the world.
The Great Commission
At the beginning of Acts, Jesus gives a task or commission to his disciples. He now calls them apostles, a Greek word meaning “messengers” or “delegates”. In summary, their commission is as to be witnesses:
You will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth. (Acts 1:8, ESV)
They are to tell people about the words and deeds of Jesus, and so become a world-wide movement of gospel preaching. (We find the same commission in more detail in Matthew 28:19: “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you.”)
And so it happens. Acts reports about many missionary journeys. In the last chapter, we find the apostle Paul in Rome, the capital city of the world, preaching the gospel to all who will hear. And in the missionary activity of the church today, we recognize that the Great Commission continues to be carried out.
The Ascension of Jesus
The gospels reported the birth, ministry, death, and resurrection of Jesus. The story continues in Acts. For 40 days after his resurrection, Jesus appears to his disciples. Then he is taken up into heaven, much like the Old Testament prophet Elijah.
And when he had said these things, as they were looking on, he was lifted up, and a cloud took him out of their sight. (Acts 1:9, ESV)
This departure from earth and entering into heaven is called the Ascension. In many European countries, Ascension Day (the Thursday nearly 6 weeks after Easter Sunday) is a national holiday.
While the Ascension seems to mark the absence of Jesus, the Bible presents it in a positive way. First of all, Jesus’ entrance into heaven means that he is glorified. The Bible depicts him as sitting “on the right hand of God,” that is, in the place of honour and authority. Second, Jesus had told his disciples that he would prepare a place for them. As the glorified King, he is getting both heaven and earth ready for the final stage of history, when all the faithful will join him in heaven. Third, Jesus promised the coming of a Helper to be with his disciples after the Ascension. This helper is identified as the Holy Spirit.
Pentecost
After the ascension of Jesus, the disciples remain together in a house somewhere in Jerusalem. After ten days, remarkable events take place that attract much attention. First of all, there is a loud noise in the house, as if there were a storm. Second, flames of fire are visible on Jesus’ disciples. Third, when the disciples talk about Jesus, the bystanders all hear the gospel in their own local language. This is remarkable, since a large group of Jews (and “god-fearers”) from many nationalities was present in Jerusalem because of Jewish holiday. (In Greek, this holiday is called “pentecost”; we now use the name Pentecost for this specific Christian event.)
All three signs point to the arrival of the Holy Spirit, which empowers the disciples to prophesy about Jesus. Acts 2 reports a marvellous sermon by Peter, in which he explains who Jesus is and what his death and resurrection mean. At the end of this day of Pentecost, about 3000 people acknowledge that Jesus is indeed the Christ and the Lord, and they are baptized. This marks the explosive beginning of the Christian church in Jerusalem.
The Holy Spirit
Jesus called the Holy Spirit “the Paraclete”, that is, “helper” or “comforter” or “advocate” (John 14:16ff). In the New Testament he represents the presence and power of the Lord Jesus. The Holy Spirit gives people the courage and wisdom to speak about Jesus. The Holy Spirit inspires prophets and gives insight to apostles. While the Holy Spirit is mentioned occasionally in the Old Testament, in the New Testament he is the dominant force in the church. For this reason, we call Pentecost the “outpouring” of the Holy Spirit. All Christian believers receive this Spirit; throughout Acts, Luke emphasizes the presence of the Spirit whenever people come to believe.
While the Holy Spirit never takes centre stage (Jesus does), Christians soon recognized that the Holy Spirit is nothing less than God himself. For this reason, the ancient Nicene Creed says that he “together with the Father and the Son is worshipped and glorified”.