It was 49 days since Passover — 49 days since Jesus was crucified on a roman cross just outside the walls of Jerusalem. Jesus’ followers were meeting together in the Upper Room.
The next holy day on Israel’s calendar was the Festival of Weeks, also known as Shavuot in Hebrew, which was originally a harvest festival. Later, the day was also used to commemorate the giving of the Law to Moses at Mount Sinai. “Weeks” comes from an expression in Leviticus 23:16, which instructs the Israelites to count seven weeks – or 49 days — from the end of Passover to the beginning of the next feast in their annual cycle of holy days. The English word, Pentecost, comes from a Greek derivation of the word, meaning “fifty” or “fiftieth day.”
The Israelites had celebrated Pentecost for centuries. However, this one would be something quite different. Here’s what we learn from Acts, Chapter 2:
When the day of Pentecost came, they were all together in one place. Suddenly a sound like the blowing of a violent wind came from heaven and filled the whole house where they were sitting. They saw what seemed to be tongues of fire that separated and came to rest on each of them. All of them were filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them.
Now there were staying in Jerusalem God-fearing Jews from every nation under heaven. When they heard this sound, a crowd came together in bewilderment, because each one heard their own language being spoken. Utterly amazed, they asked: “Aren’t all these who are speaking Galileans? Then how is it that each of us hears them in our native language? … — We hear them declaring the wonders of God in our own tongues!” Amazed and perplexed, they asked one another, “What does this mean?” (Acts 2:1-12)
The commotion surrounding Pentecost didn’t go unnoticed. Rumors started spreading through the streets of Jerusalem, and crowds started gathering in the area, just west of the temple complex. At some point, Peter moved to the front of the growing crowds with newfound boldness. He raised his voice and began addressing the curious crowd – delivering what many consider his first sermon.
Peter started with background that would be familiar to his local audience. He referenced Hebrew prophecy and God’s promise to pour out His Spirit as a sign of the coming “day of the Lord.” Peter then connected what everyone had just witnessed to the fulfillment of God’s centuries-old promise. He went on to declare other promises to the Israelites, including the long-awaited Messiah taking the throne of King David. Peter again connected these promises to Jesus, who they had crucified, but who God raised from the dead.
“Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit. The promise is for you and your children and for all who are far off—for all whom the Lord our God will call.” (Acts 2:38-39)
This account of Pentecost goes on to tell us that about 3,000 people accepted Peter’s message and were baptized that day. From 120 disciples in hiding to a public movement of over 3,000 Jesus followers in just one day — it was the beginning of what would later be called the “Christian church.” In fact, many Christians today call this event at Pentecost the “birthday of Christianity.”