Who were the people Peter and John were speaking to in Acts 4?
In Acts 4, Peter and John were speaking to the Jewish nation, specifically the priests, the captain of the temple, and the Sadducees. All of these were Jews, with no Gentiles involved. The Sadducees were especially grieved because Peter preached through Jesus the resurrection from the dead, which contradicted their doctrine that there is no resurrection.
Les teaches that as Peter and John spoke to the people in Acts 4, the audience was the Jewish nation—the priests, the captain of the temple, and the Sadducees. He stresses that every one of them was a Jew, and no Gentiles were involved in the temple priesthood, the Sadducees, or the Pharisees. The Sadducees were the group most concerned about Peter's preaching because they denied any resurrection from the dead. They challenged Peter for teaching something contrary to their doctrine, namely that Christ was alive and able to come as their King.