What does Acts 2:36 mean?
Peter finishes the first sermon of the church age by presenting three incredible truths: Jesus of Nazareth is the Messiah sent by God to save the Jews; the Jews killed Him; God raised Him from the dead, giving the Jews hope for their own resurrection. As Jesus promised, the apostles and other Jesus-followers will spread variations of this message "in Jerusalem and in all Judea and Samaria, and to the end of the earth" (Acts 1:8). Peter's message is directed to the Jews in Jerusalem, but Jesus has already said the message is for everyone on earth (John 10:16). Because, the truth is, Jesus came to save all of us; we all, with our sin, killed Him; and God raised Him from the dead to give us all hope.The truths in Peter's message in Acts 2:14–36 carried his audience through an extraordinary range of ideas. The crowd gathered in the first place because the Holy Spirit came on 120 Jesus-followers who started speaking different languages and dialects (Acts 2:4–13) as Joel prophesied (Acts 2:17–18). Joel also wrote that those who do not pay attention to these signs will be counted as God's enemy and treated as such (Acts 2:19–20). But there is yet time to turn to Him (Acts 2:21).
Then Peter shows his audience how this relates to Jesus. Peter's Jewish audience, either directly or through proxy by being of the Jewish nation, took a Man who was also marked by God's miracles and crucified Him (Acts 2:22–23). But God not only raised Him from the dead, His resurrection brings hope for theirs, as well (Acts 2:24–35).
After such a speech of signs, condemnation, and hope, it's no wonder Peter's audience responds, "Brothers, what shall we do?" (Acts 2:37). Fortunately, when Jesus called His followers to be His witnesses (Acts 1:8), the message they were given was never just to convict others of sin; it was always to lead to repentance, as Peter tells them, "for the forgiveness of your sins, and you will receive the gift of the Holy Spirit" (Acts 2:38).