The word ‘pentecost’ means ‘fifty’, and comes from the Greek translation of the Old Testament. It refers to the Israelite harvest festival that was held fifty days after Passover. In the Old Testament this festival is called the Feast of Harvest, the Feast of Firstfruits and the Feast of Weeks. In the New Testament it is called the Feast of Pentecost (Leviticus 23:5-6; Leviticus 23:15-16; Acts 2:1; Acts 20:16; 1 Corinthians 16:8; for details see FEASTS).
Pentecost is significant in the New Testament story because on that day the church was born. Christ the Passover lamb had been sacrificed; then, fifty days later, God poured out his Spirit on that small group of disciples who were the firstfruits of his new people, the church of Jesus Christ (Acts 2:1-4; cf. 1 Corinthians 5:7). (Concerning the extraordinary happenings that day see BAPTISM WITH THE SPIRIT; TONGUES.)