On the day of Pentecost, the followers of Jesus were gathered together in Jerusalem. They had been waiting, as Jesus had instructed, for the promise of the Holy Spirit. Suddenly, there was a sound like a mighty rushing wind, and it filled the house where they were sitting. Tongues of fire appeared above each of them, and they were all filled with the Holy Spirit. They began to speak in different languages, as the Spirit enabled them. People from many nations were in Jerusalem at that time, and they were amazed to hear the disciples speaking in their own languages about the wonders of God. Peter then stood up and addressed the crowd, explaining that this was the fulfillment of the prophecy from the book of Joel. He preached about Jesus, who had been crucified and resurrected, and called on the people to repent and be baptized. Many believed his message, and about three thousand people were baptized that day, marking the beginning of the Christian church.