The Acts of the Apostles, the second volume of Luke's two-volume work, continues Luke's presentation of biblical history, describing how the salvation promised to Israel in the Old Testament and accomplished by Jesus has now under the guidance of the holy Spirit been extended to the Gentiles. This was accomplished through the divinely chosen representatives (Acts 10:41) whom Jesus prepared during his historical ministry (Acts 1:21–22) and commissioned after his resurrection as witnesses to all that he taught (Acts 1:8; 10:37–43; Lk 24:48). Luke's preoccupation with the Christian community as the Spirit-guided bearer of the word of salvation rules out of his book detailed histories of the activity of most of the preachers. Only the main lines of the roles of Peter and Paul serve Luke's interest.

Peter was the leading member of the Twelve (Acts 1:13, 15), a miracle worker like Jesus in the gospel (Acts 3:1–10; 5:1–11, 15; 9:32–35, 36–42), the object of divine care (Acts 5:17–21; 12:6–11), and the spokesman for the Christian community (Acts 2:14–36; 3:12–26; 4:8–12; 5:29–32; 10:34–43; 15:7–11), who, according to Luke, was largely responsible for the growth of the community in the early days (Acts 2:4; 4:4). Paul eventually joined the community at Antioch (Acts 11:25–26), which subsequently commissioned him and Barnabas to undertake the spread of the gospel to Asia Minor. This missionary venture generally failed to win the Jews of the diaspora to the gospel but enjoyed success among the Gentiles (Acts 13:14–14:27).

Paul's refusal to impose the Mosaic law upon his Gentile converts provoked very strong objection among the Jewish Christians of Jerusalem (Acts 15:1), but both Peter and James supported his position (Acts 15:6–21). Paul's second and third missionary journeys (Acts 16:36–21:16) resulted in the same pattern of failure among the Jews generally but of some success among the Gentiles. Paul, like Peter, is presented as a miracle worker (Acts 14:8–18; 19:12; 20:7–12; 28:7–10) and the object of divine care (Acts 16:25–31).

In Acts, Luke has provided a broad survey of the church's development from the resurrection of Jesus to Paul's first Roman imprisonment, the point at which the book ends. In telling this story, Luke describes the emergence of Christianity from its origins in Judaism to its position as a religion of worldwide status and appeal. Originally a Jewish Christian community in Jerusalem, the church was placed in circumstances impelling it to include within its membership people of other cultures: the Samaritans (Acts 8:4–25), at first an occasional Gentile (Acts 8:26–30; 10:1–48), and finally the Gentiles on principle (Acts 11:20–21). Fear on the part of the Jewish people that Christianity, particularly as preached to the Gentiles, threatened their own cultural heritage caused them to be suspicious of Paul's gospel (Acts 13:42–45; 15:1–5; 28:17–24). The inability of Christian missionaries to allay this apprehension inevitably created a situation in which the gospel was preached more and more to the Gentiles. Toward the end of Paul's career, the Christian communities, with the exception of those in Palestine itself (Acts 9:31), were mainly of Gentile membership. In tracing the emergence of Christianity from Judaism, Luke is insistent upon the prominence of Israel in the divine plan of salvation (see note on Acts 1:26; see also Acts 2:5–6; 3:13–15; 10:36; 13:16–41; 24:14–15) and that the extension of salvation to the Gentiles has been a part of the divine plan from the beginning (see Acts 15:13–18; 26:22–23).

In the development of the church from a Jewish Christian origin in Jerusalem, with its roots in Jewish religious tradition, to a series of Christian communities among the Gentiles of the Roman empire, Luke perceives the action of God in history laying open the heart of all humanity to the divine message of salvation. His approach to the history of the church is motivated by his theological interests. His history of the apostolic church is the story of a Spirit-guided community and a Spirit-guided spread of the Word of God (Acts 1:8). The travels of Peter and Paul are in reality the travels of the Word of God as it spreads from Jerusalem, the city of destiny for Jesus, to Rome, the capital of the civilized world of Luke's day. Nonetheless, the historical data he utilizes are of value for the understanding of the church's early life and development and as general background to the Pauline epistles. In the interpretation of Acts, care must be exercised to determine Luke's theological aims and interests and to evaluate his historical data without either exaggerating their literal accuracy or underestimating their factual worth.

Finally, an apologetic concern is evident throughout Acts. By stressing the continuity between Judaism and Christianity (Acts 13:16–41; 23:6–9; 24:10–21; 26:2–23), Luke argues that Christianity is deserving of the same toleration accorded Judaism by Rome. Part of Paul's defense before Roman authorities is to show that Christianity is not a disturber of the peace of the Roman Empire (Acts 24:5, 12–13; 25:7–8). Moreover, when he stands before Roman authorities, he is declared innocent of any crime against the empire (Acts 18:13–15; 23:29; 25:25–27; 26:31–32). Luke tells his story with the hope that Christianity will be treated as fairly.

Concerning the date of Acts, see the Introduction to the Gospel according to Luke.

The principal divisions of the Acts of the Apostles are the following:

The Preparation for the Christian Mission (1:1–2:13)

The Mission in Jerusalem (2:14–8:3)

The Mission in Judea and Samaria (8:4–9:43)

The Inauguration of the Gentile Mission (10:1–15:35)

The Mission of Paul to the Ends of the Earth (15:36–28:31)