Answer
The book of Acts—also known as the Acts of the Apostles—records the early church’s birth and growth, beginning with Jesus’ resurrection and ending with Paul at Rome. The title is derived from the Greek term praxis, signifying action. The book of Acts was written by Luke, the author of the Gospel that bears his name.
While Acts serves as a historical document, its purpose goes beyond providing an impersonal church history. Acts vividly depicts the Holy Spirit’s vibrant spread of the gospel, from Jews to Samaritans to Gentiles (Acts 2:1–4; 8:14–17; 10:44–48), in alignment with Jesus’ statement, “But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth” (Acts 1:8).
The opening line of Acts reveals it to be a sequel to the Gospel of Luke, with Theophilus being the recipient of both works. Consequently, Luke and Acts form a cohesive two-volume work known as Luke-Acts. Christian tradition holds that Luke, a doctor and companion of Paul, wrote both works. An ancient prologue revealed that Luke first accompanied the apostles before becoming Paul’s companion, which explains the trajectory of the history in Acts. The early church was unanimous in attributing the book of Acts to Luke. We also have internal evidence that the author witnessed some of the events and participated in Paul’s second and third missionary journeys (Acts 16:10–17; 20:5–6; 21:1–18).
A common objection to the authorship of Acts is the alleged contradictions between Acts and the Pauline Epistles. An example of an alleged contradiction is the difference between Galatians 1:16–20 and Acts 9:19–30 concerning the time immediately after Paul’s conversion. Did Paul spend three years before going to meet the apostles in Jerusalem as he said in Galatians? Or did he head directly to Jerusalem, as Luke seems to imply? A closer look at Acts 9 reveals that Luke didn’t say Paul went directly to Jerusalem from Damascus. In verses 19–22, Paul remained in Damascus, just as he says in Galatians. In verses 23–25, Luke writes, “After many days had gone by, there was a conspiracy among the Jews to kill him, but Saul learned of their plan. Day and night they kept close watch on the city gates in order to kill him. But his followers took him by night and lowered him in a basket through an opening in the wall.” Sometime after that, Paul went to Jerusalem. The alleged contradiction is resolved simply by recognizing that Luke abridged his version of the narrative using the phrase after many days to cover the whole of Paul’s trip to Arabia and his time spent in Damascus. Thus, Luke isn’t contradicting Paul; he simply leaves out details he deemed unnecessary to his account.
Of course, alleged contradictions don’t cancel out Luke’s authorship of Acts. At worst, it calls into question his reliability as a historian. But there are reasoned responses to all the so-called contradictions (see https://crossexamined.org/is-bart-ehrman-right-when-he-says-that-acts-contradicts-pauls-letters/), and Luke is widely considered an astute historian.
