The author of the book of Acts is unknown, but church tradition ascribes it to Luke who also is thought to have written the Gospel of Luke. Acts was composed in the early 60s during the reign of Emperor Nero. It is a historical account of the journey of the Apostles and starts from the final days of Jesus’ ministry and continues until the end of Paul’s ministry.
In the first chapter, Jesus’ Ascension is described, when He called the Apostles to spread the gospel to all peoples of the earth and were also instructed to speak in the languages of the people to whom they preached. Declaring Jesus as the fulfillment of older prophecies, Peter cited Joel 2. Since Jesus had departed, the Apostles were given the power to heal the sick. This caused conflict with the Sadducees, who forbade them from performing miracles in Jesus’ name. Despite being arrested, the Apostles refused to remain silent. After escaping by a miracle, they proclaimed that they must obey God, not men.
Witnessing the martyrdom of Stephen by the Sadducees, Saul was a persecutor of Christians. Persecution did not work as intended against the Christians, whose faith was only strengthened by it. While on the road to Damascus to kill Christians, Saul was converted to Christianity by divine will and adopted the name Paul. Consequently, Peter abandoned his exclusive commitment of preaching only to Jews after being convinced by Paul that the Gentiles must too receive the good news. In Antioch, the term “Christians” is first used.
The focus of the book was historical and the goals of the author were to: continue the story of the church post-Ascension, explain the opposition of the religious leaders, chronicle the growth of the Church on Pentecost and after, document the development of the Church as an institution where authority shifted away from Jesus to the Apostles, show the expansion of the Church to Samaria, Ethiopia, and Antioch, show the transition away from Mosaic dietary laws, and affirm the equality of the Gentiles in the Church. Having authority to work miracles and receive commands from the Holy Spirit, the Apostles were also a source of doctrine.
The theme of the stories that are told in the book of Acts is the expansion of the early Church and the ministry of the Apostles. The stories show continuity: prophecy and fulfillment. Christianity was not thought of as the religion of one people, as it extended across borders and languages. Instead, Baptism was the sign of the New Covenant.