Acts is the only surviving narrative history of the earliest church, which makes it indispensable and also leaves it without a rival to be checked against — except at the points where Paul writes about the same events himself.
What the book is
Twenty-eight chapters carrying the story from the resurrection appearances to Paul under guard in Rome, covering some thirty years. It is the second half of a two-volume work. The opening sentence refers back to a former book written for the same patron, Theophilus, and the Gospel of Luke opens by addressing him; the vocabulary, sentence construction and interests of the two are close enough that common authorship is among the least disputed positions in the field.
Like the Gospel, it is formally anonymous. The name Luke, the physician mentioned in passing in Paul’s letters, is a second-century attribution, and “the Acts of the Apostles” is a later heading rather than the book’s own title. The heading oversells the contents: most of the twelve disappear early, and the book is substantially about two men, Peter and then Paul.
How it is put together
The design is stated in the first chapter: witnesses in Jerusalem, in all Judaea and Samaria, and to the end of the earth. The narrative then executes that programme outward — Jerusalem, the Judaean and Samaritan countryside, Antioch, Cyprus, Asia Minor, Greece, and finally Rome — with short summary sentences about the word spreading marking the joints between stages.
A large share of the book is speech: Peter at Pentecost, Stephen before the council, Paul at Athens and to the elders at Miletus, and the defence speeches at the end. These are not transcripts, and no ancient reader would have expected them to be. Greek historiography had an established convention, stated openly by Thucydides, that a historian composed the speech appropriate to the speaker and the occasion while keeping as near as he could to the general sense of what was said. Acts follows that convention. The speeches are in the author’s Greek and shaped to the book’s argument, which is a statement about genre rather than an accusation of bad faith — though it does mean a speech in Acts cannot be treated as a record of words spoken.
Partway through, the narration changes person. In several passages, mostly involving sea travel, the story is told as “we” rather than “they”, and then reverts. Three explanations are in play. The author was present at those stages and is signalling it. The author was working from a travel diary kept by a companion and left its first person standing. Or the first person plural is a literary device, used to lend immediacy — sometimes supported by appeal to a convention in ancient sea-voyage narrative, though whether that convention existed is itself disputed. The first is the traditional explanation and remains widely held; nothing in the text settles the choice.
The dating question
Conventional ranges put Acts in the 80s or 90s CE, after the Gospel it continues. That is contested in both directions. An early date, around 62, is argued chiefly from the ending: the book stops with Paul alive in Rome and says nothing of his death, which is easiest to explain if it had not yet happened. A date in the early second century is argued from the book’s picture of a church already settling into structures, and from proposed contacts with the works of Josephus. Tied to the Gospel as it is, its date also moves with the dating of Luke. See how we date a text.
Where the external record touches it
Acts is unusually specific about civic detail, and the detail is unusually often right. Thessalonica’s magistrates are called politarchs, an uncommon title attested for that city in inscriptions; Cyprus and Achaia are governed by proconsuls, which is correct for senatorial provinces; Philippi behaves like the Roman colony it was; Ephesus has its Asiarchs and its assembly; the leading man of Malta carries a title used there. This is a real feature of the book. It is also worth stating what it shows: a writer well informed about the administration of the eastern empire. Accurate settings are evidence about the author’s knowledge. They are not, on their own, evidence that a particular episode set in them took place.
Two individuals in the narrative are touched by inscriptions. Gallio, before whom Paul is brought at Corinth, is named in an inscription found at Delphi that records a letter of the emperor Claudius, and the imperial titles in it place his year as proconsul of Achaia at about 51 or 52 CE. It is the firmest fixed point in Pauline chronology, and most reconstructions hang on it. Erastus, named in Paul’s letter to the Romans as the city treasurer at Corinth, shares a name with the Erastus of a paving inscription found at Corinth, who laid the pavement at his own expense in return for office. Whether the two are the same man is argued both ways; the name was not rare, and the offices are not obviously the same. See what external attestation means.
The sharpest external check on Acts is Paul himself, because his letters are first-hand and address some of the same events. They do not fit together easily. Galatians gives a first-person account of Paul’s visits to Jerusalem after his conversion that is difficult to line up with the sequence of visits in Acts, and Paul writes as though the count matters. The meeting about gentile converts in Acts 15 is usually identified with the private conference Paul describes in Galatians 2, but the two accounts differ in setting, participants and outcome, and the decree Acts says was issued goes unmentioned in Paul’s letters even where the subject would demand it. Harmonisations exist, and some are careful; others conclude that the author of Acts wrote without access to the letters and reconstructed from tradition. Both are positions.
The ending
The book stops rather than concludes. Paul is in Rome, under a loose custody, receiving visitors and preaching without hindrance for two years — and that is the last sentence. There is no trial, no verdict and no death. The proposed explanations are that the author wrote before the outcome was known, that he had reached his real goal when the message reached Rome and had no more to say, that a third volume was intended, or that the outcome was known and deliberately not recorded. Nothing in the text decides between them.
Where to start
Read Acts 15 and Galatians 1 and 2 one after the other, in that order, with a pencil. It takes twenty minutes, and it is the best exercise there is in what it means for two sources to describe the same events differently. Then read the last chapter and notice how little it settles. Errors on this page are recorded in the corrections log.