They were speaking to the people in the temple when the priests, the captain of the temple, and the Sadducees came upon them (Acts 4:1). Acts says the leaders were annoyed because they were teaching and proclaiming in Jesus the resurrection from the dead (Acts 4:2).
While Peter and John are addressing the crowd, temple authorities move in: priests, the temple captain, and Sadducees. They are irritated because the teaching publicly links Jesus with resurrection. The two men are seized and held overnight since it is already evening. This scene continues directly from the healing at the temple gate and Peter’s public explanation to the crowd in Acts 3:1–26. Acts often moves from a public act or speech to a confrontation with authorities, showing how the message spreads and how opposition forms.
Acts 4:1–7 presents the first organized pushback against the apostles’ public message after the temple healing in Acts 3. The text is clear that the trigger is not only the public disturbance but the content: they are “teaching the people” and announcing “resurrection from the dead” in connection with Jesus (verses 1–2).
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with Acts 4:1, then read the surrounding section so the answer stays connected to the passage's flow.
1As they spoke to the people, the priests and the captain of the temple and the Sadducees came to them,