There are a number of similarities between events on Acts 2 and 3. Apparently Peter and John regularly went up to the temple for prayer and worship. While they were there, they had opportunity to preach Jesus as the messiah. The gospel of the risen and ascended Jesus would have been of interest to some of the Jews who were also at the Temple worship. Prior to both Peter’s sermons in Acts 2-3 God did a miracle to demonstrate the messianic age has begun. The coming of the Holy Spirit and the healing of a lame man are both based on messianic prophecies found in the Hebrew Bible. Peter clearly declares Jesus was the messiah and he was crucified in ignorance. But this ignorance will no longer be overlooked and judgment is coming. After both sermons thousands of people believe Jesus is the messiah and he is returning soon to establish his kingdom.
After healing the lame man and preaching to another large crowd, the Temple authorities arrest Peter and John (Acts 4). As Ben Witherington comments, Acts 4 is the “beginnings of the power struggle for the hearts of the Jewish people” (Acts, 189). For the next several chapters there is increasing tension and persecution between the ministries of the twelve Apostles and the seven deacons, culminating in the execution of Stephen at the end of chapter 7. Preaching the Gospel, as it turns out, is a very dangerous thing to do!
Peter and John are brought before Annas and Caiaphas, the high priests responsible for the crucifixion of Jesus (Luke 22:54, cf., John 11:49). The group which is gathered includes the elders and teachers of the Law, including the high priest Annas, and men from his family, Caiaphas, John and Alexander.
There is a historical problem here. Annas was high priest from A.D. 6-15, his son-in-law Caiaphas was high priest from A.D. 18-36. There are several explanations for this. One possibility is that Luke lists Annas as the high priest since he is the real power behind Caiaphas (this is at least the view of John 18:13, since Jesus is brought to Annas before he is brought to Caiaphas, the actual high priest). Caiaphas’s name has been found on a rather ornate ossuary (which does not appear to be a forgery, although Craig Evans doubts the name is the biblical Caiaphas, see Craig A. Evans, “Jesus and the Ossuaries,” Bulletin for Biblical Research 13 [2003]: 39).
Since whole Sanhedrin could have been as many as seventy men, it is unlikely the whole council met to question Peter. This is probably the high priest and his closest advisers and the questioning is intended to find out who authorized the apostles to declare publicly Jesus was the messiah (4:7). For Caiaphas and the others who were involved in Jesus’ execution, the claim God raised Jesus from the dead is more than just awkward, it is an attack on them as legitimate authority. They found Jesus guilty and killed him; God found him innocent and raised him from the dead. Since Caiaphas and his advisers are Sadducees, they reject the possibility Jesus was the Messiah and especially that God raised him from the dead.
As Craig Keener points out, preaching in the Temple was not illegal, nor was healing a lame man or drawing a large crowd (2:1135). But it was extremely dangerous to declare a man who was executed as a false messiah was in fact the God’s messiah. It is a direct attack on the Temple aristocracy who killed Jesus. If the disciples continue to preach this message to the crowds, they will face increasing persecution from the aristocratic priesthood in Jerusalem.
Why do the disciples remain in Jerusalem? Could they not simply return to Galilee and preach the same gospel in a safer place? Why does Peter insist on emphasizing the participation of his audience in the death of Jesus? He seems to be attacking the Temple aristocracy directly, why does Peter not find a less-offensive way of preaching the Gospel?