Though various Christian denominations commemorate Pentecost, many forget that it was a Jewish holiday before the Church was established. The name Pentecost comes from the Greek word for fifty, but the Jewish name is Shavuot (meaning weeks or sevens).
Traditional Jews of Jesus' time celebrated Pentecost (or Shavuot) on the fiftieth day after the waving of the firstfruits. (Firstfruits coincided with the Feast of Unleavened Bread.) The firstfruits wave offering consisted of a sheaf of barley, the first crop of the spring growing season. This early growing season ended seven weeks later with the cutting of the wheat harvest, and for that crop, a different kind of offering was decreed. We find the Old Testament commandment for Shavuot, the Feast of Weeks, and its required offering in Leviticus 23:15-17:
And you shall count for yourselves from the day after the Sabbath, from the day that you brought the sheaf of the wave offering: seven Sabbaths shall be completed.
Count fifty days to the day after the seventh Sabbath; then you shall offer a new grain offering to the Lord.
You shall bring from your habitations two wave loaves of two-tenths of an ephah. They shall be of fine flour; they shall be baked with leaven. They are the firstfruits to the Lord.
Even in early times, a diversity of opinions existed about the date of Shavuot. There were two major schools of thought on the interpretation of the Leviticus 23 text. The Sadducees interpreted Sabbath in verse 15 to mean the literal seventh day of the week, so that the barley sheaf was to be offered on the first Sunday of Passover or the Feast of Unleavened Bread. Then Shavuot would always fall on the seventh Sunday after Passover. The Pharisees, however, interpreted "Sabbath" not literally as Saturday, but figuratively, as the day of rest to be observed on the first day of the Feast of Unleavened Bread. That would be the fifteenth of the Jewish month Nisan, regardless of what day of the week it was. Based on this interpretation, the barley offering would be made on the sixteenth of Nisan, and Shavuot would come seven weeks later, on the sixth day of the month Sivan, on whatever day of the week it might fall. As long as the Temple stood and the Sadducees were in charge, their view prevailed. Today, however, the date of Shavuot is based on the generally accepted interpretation of the Pharisees.
Along with variations in date, diversities also arose in the understanding of the holiday's purpose. Though Shavuot was originally a time of thanksgiving for the wheat harvest, it became more than just a harvest festival to the Jewish people. The Book of Jubilees (of Second Temple times) indicates that Shavuot was also celebrated as an annual memorial of God's promise to Noah never again to destroy the world by flood.
More widely accepted today is the idea, based on rabbinic calculations, that Shavuot was when God gave the Law to Moses on Mount Sinai, and the holiday has become a time for commemorating that occasion. To celebrate the Giving of the Law, the Ten Commandments are read in the synagogue on the first day of the weeklong festival, and plants and flowers reminiscent of the slopes of Mount Sinai decorate the sanctuary. To honor the original harvest aspect of the holiday, the liturgy also includes the Book of Ruth because of its setting of summer harvest time in Israel.
For believers in Yeshua, Shavuot becomes an archetype of what happened seven weeks after the crucifixion and resurrection of Yeshua. Because of the great power displayed in the upper room at Pentecost, some regard this day as celebrating the advent of the Holy Spirit. Yet that was not quite the case. We read in John 20:21,22 that the risen Christ breathed on each of the disciples and filled them with the Holy Spirit weeks before Pentecost!
The event of Pentecost was the "birthday" of the Church—the welding together of Spirit-filled disciples into one organism—the living body of Christ. At Pentecost, the Holy Spirit moved upon each of the disciples to bring about the united story of the Church. Just as the Giving of the Law at Sinai formed the constitution of the spiritual commonwealth of Israel, so the visible manifestation of the Holy Spirit upon the disciples signaled the constitution of the spiritual community of faith in Christ. In the first case, Israel was brought together by the Law (rules of constitution), in the latter, believers in Christ were bonded together not by rules, but by the Holy Spirit within them.
The entire spring religious season of Israel, from Passover to Pentecost, speaks of God's plan to harvest a holy people for Himself. First, Yeshua died as the perfect, sinless sacrifice. Then, He arose and became the firstfruits from the dead as described by the apostle Paul in 1 Corinthians 15:20. Seven weeks after the resurrection, the dynamic manifestation of the Holy Spirit among the early Jewish believers became the catalyst for many to put their faith in God's Messiah. The Jewish pilgrims at Jerusalem who heard and received the good news of salvation joyfully brought it back to their native lands. There, it was received by Gentiles as well as by other Jews, an the Church became established abroad.
Thus, the inclusion of the Gentiles completed the symbolism of the wave offering, where the High Priest offered two loaves of fine wheat flour baked with leaven. Centuries before it came to pass, the two loaves of the wave offering symbolized the Body of Messiah made up of both Jewish and Gentile believers. Though the loaves were made of fine wheat flour, they contained leaven, a symbol of sin. That speaks of the fact that the Church, though refined (cleansed by the blood of Yeshua's sacrifice), still retains the human sin nature until that day when she will be presented as the Bride of Christ, without spot or wrinkle.
Today, Pentecost should speak to us of the sowing of gospel seed and the harvest or ingathering of saved souls—redeemed people to become part of the Body of Christ. God wants such a harvest from every kindred tribe and nation.
Some wrongly think that the chief purpose of the Church is to provide a place for people to worship and enjoy God. This view of only one function of the Body as its prime purpose generates an "upper room" mentality that has us huddled together, waiting for God to act. Surely there are times when we ought to wait on the Lord for His empowerment, but He wants an active, dynamic Church to bring His message of salvation to the ends of the earth (Acts 1:8). He doesn't want us to remain in seclusion waiting for miracles. He wants us to go out among those who do not know Christ to tell them, in the power of the Holy Spirit, of God's salvation.
The test of Pentecost is not what happened in the upper room but what happened on the streets afterward. "The Lord added to the Church daily those who were being saved" (Acts 2:47b). As we celebrate the birthday of the Church, we would do well to contemplate the fact that our primary purpose is to proclaim the gospel. As we, God's people, remain faithful to this task, the harvest will grow.