Peter has been explaining that the apostles’ ability to speak in unlearned foreign languages is a gift of the Holy Spirit and a confirmation that we are living in the last days. He has also explained that the Spirit was poured out from heaven by Jesus of Nazareth who is the Christ of God. This is the same Jesus who was crucified two months previously with the support or approval of the Jews to whom he is now speaking. The people have thus come to understand that they were involved with and bear responsibility for the death of the Messiah.1 They rejected Jesus despite all the evidence.2
37 Now when they heard this they were cut to the heart, and said to Peter and the rest of the apostles, “Brothers, what shall we do?”