What does Acts 4:8 mean?

Luke records two of Peter's sermons since Jesus ascended into heaven: to a group of Jewish travelers who had come to Jerusalem for Pentecost (Acts 2:14–41) and to a crowd at the temple who had seen him heal a lame man (Acts 3:11–26). Likely, he has preached many more times. This is the first recorded time that he answers charges brought by the Sanhedrin, the Jewish ruling council.

In fact, this may be the first time Peter has stood before the high priest Annas since he denied Jesus in Annas's courtyard (John 18:12–27). Shortly before, during the Last Supper, Peter had insisted he would die for Jesus (Matthew 26:33–35). But that was before the soldiers came, before Peter impulsively sliced off the high priest's servant's ear, and before Peter stood before that servant's relative in Annas's courtyard while the priest's guards beat Jesus (John 18:10, 26–27, 22).

The difference is the Holy Spirit. Jesus promised His disciples that when He returned to heaven, He would send a Helper to tell them what to say (John 14:16–17, 26). The Holy Spirit came to the Jesus-followers about ten days after Jesus ascended (Acts 2:1–4). When needed, the Holy Spirit fills them, giving them godly courage and guidance as to what they should say. In fact, Jesus promised them, "When they deliver you over, do not be anxious how you are to speak or what you are to say, for what you are to say will be given to you in that hour. For it is not you who speak, but the Spirit of your Father speaking through you" (Matthew 10:19–20).

Peter, a man devoted to Jesus but always sticking his foot in his mouth, uneducated and common (Acts 4:13), stands before priests, lawyers, and civil judges. He confidently and clearly accuses them of crucifying their Messiah. As Paul will later write, " But God chose what is foolish in the world to shame the wise; God chose what is weak in the world to shame the strong" (1 Corinthians 1:27).