When the day of Pentecost arrives, the disciples are all together in one place. Suddenly a sound like a strong wind comes from heaven, tongues like fire appear and rest on each of them, and all are filled with the Holy Spirit and begin to speak in other tongues. Devout Jews from many nations gather in amazement because each one hears them speaking in his own language about the mighty works of God. Some ask what it means; others mock and say they are drunk.
Peter stands with the eleven and answers: they are not drunk, since it is only the third hour of the day; this is what the prophet Joel said, that God would pour out his Spirit on all flesh. He then preaches Jesus of Nazareth, whom they handed over and crucified, but whom God raised up. He cites David's psalms to show that the Messiah would not see decay and that God exalted him to his right hand, and concludes that God has made him both Lord and Christ.
The hearers are cut to the heart and ask what they should do. Peter calls them to repent and be baptized in the name of Jesus Christ for the forgiveness of sins and to receive the gift of the Spirit, a promise for them, for their children and for those far off. That day about three thousand are added. The chapter closes with the life of the first community: they devote themselves to the apostles' teaching, fellowship, the breaking of bread and the prayers, they share what they have, and the Lord adds to their number day by day those who are being saved.