Pentecost Sunday is a commemoration and celebration of the receiving of the Holy Spirit by the early church. John the Baptist prophesied of the first Pentecost when Jesus would baptize with the Holy Spirit and with fire (Matthew 3:11). Jesus confirmed this prophecy with the promise of the Holy Spirit to the disciples in John 14:26. He showed Himself to these men after His death on the cross and His resurrection, giving convincing proofs that He was alive. Jesus told the disciples to wait in Jerusalem for the Father’s gift of the Holy Spirit, from whom they would receive power to be His witnesses to the ends of the earth (Acts 1:3-8). After Jesus’ ascension to heaven, the men returned to Jerusalem and joined together in prayer in an upper room. On the Day of Pentecost, just as promised, the sound of a violent wind filled the house and tongues of fire came to rest on each of them and all were filled with the Holy Spirit. They were given the power of communication, which Peter used to begin the ministry for which Jesus had prepared him. After the coming of the Holy Spirit, the disciples did not stay in the room basking in God’s glory but burst out to tell the world. This was the beginning of the church as we know it.