What does the Bible say about the Day of Pentecost?

The Day of Pentecost, celebrated in Acts 2, signifies the outpouring of the Holy Spirit upon the followers of Jesus, fulfilling the prophecies made by Joel. It transitioned the Jewish feast, initially a thanksgiving for the wheat harvest, into a celebration of the new covenant established through Christ. The apostles, particularly Peter, proclaimed the message to the people, emphasizing that Jesus, crucified by their sins, has been made both Lord and Christ. This occasion resulted in the conversion of about 3,000 souls, indicating the profound impact of the Holy Spirit at work.