Exerpts from The Acts of the Apostles, Chapters 1 and 2 (NRSV):
"While staying with them, [Jesus] ordered them not to leave Jerusalem, but to wait there for the promise of the Father. 'This,' he said, 'is what you have heard from me; for John baptized with water, but you will be baptized with the Holy Spirit not many days from now.'
". . .When the day of Pentecost had come, they were all together in one place. And suddenly from heaven there came a sound like the rush of a violent wind, and it filled the entire house where they were sitting. Divided tongues, as of fire, appeared among them, and a tongue rested on each of them. All of them were filled with the Holy Spirit and began to speak in other languages, as the Spirit gave them ability.
". . . But Peter, standing with the eleven, raised hs voice and addressed them . . . This Jesus God raised up, and of that all of us are witnesses. Being therefore exalted at the right hand of God, and having received from the Father the promise of the Holy Spirit, he has poured out this that you both see and hear . . .
"Now when they heard this, they were cut to the heart and said to Peter and to the other apostles, 'Brothers, what should we do?' Peter said to them, 'Repent, and be baptized every one of you in the name of Jesus Christ so that your sins may be forgiven; and you will receive the gift of the Holy Spirit.' . . . So those who welcomed his message were baptized, and that day about three thousand persons were added. They devoted themselves to the apostles' teaching and fellowship, to the breaking of bread and the prayers.
"Awe came upon everyone . . .Day by day, as they spent much time together in the temple, they broke bread at home and ate their food with glad and generous hearts, praising God and having the goodwill of all the people . . ."
And so on Pentecost the Church was born because "Christ loved the church and gave himself up for her." (Ephesians 5:25).