According to the biblical account, Pentecost occurred fifty days after the ascension of Jesus Christ, when the disciples were gathered together in Jerusalem.During that time, the Jewish festival of Pentecost (also known as the Feast of Weeks or Harvest Festival) was being celebrated. This festival commemorated the Israelites receiving the Ten Commandments and the law from Moses. The disciples were observing this traditional festival as well.

While they were all together, they heard a sound like a rushing wind and saw tongues of fire that separated and came to rest on each of them. They were filled with the Holy Spirit and began to speak in different languages, as the Spirit enabled them. This event is famously known as the "descent of the Holy Spirit."

Peter, one of the disciples, stood up and addressed the crowd, explaining that what was happening was the fulfillment of the prophecy spoken by the prophet Joel. He proclaimed Jesus Christ as the Savior and urged the people to repent and be baptized. On that day, three thousand people believed in Jesus and were baptized, becoming part of the newly formed Christian community.

Since then, Pentecost has become an important festival for Christians, commemorating the coming of the Holy Spirit and the birth of the Church. It symbolizes the work of the Holy Spirit and the continued revelation of God among believers. Pentecost serves as a reminder to Christians of Jesus' promise and mission, inspiring them to live out their faith authentically and spread the Gospel to the ends of the earth.