The significance of Pentecost to the Jews and to Christians.
Pentecost commemorates the anniversary of the giving of the Torah by God to the Children of Israel at Mount Sinai.
The Jews were led out of bondage in Egypt.
The Jews passed from their old lives through the waters of the Red Sea into their new lives with God leading them.
Moses went up the mountain to speak with God. When he came down the mountain with the ten commandments Moses's face shined with the Divine Glory of God.
Christians are led out of bondage to Sin.
Christians are led out of their old lives through the waters of baptism into their new lives with God leading them
Jesus rose into Heaven and sent The Holy Spirit down to empower Christians with the power of God.
When this first happened "... suddenly there came from heaven a noise like a violent rushing wind, and it filled the whole house where they were sitting. And there appeared to them tongues as of fire distributing themselves, and they rested on each one of them."
The context of these events would have been immediately obvious and powerfully convicting to the Jews on that day described in Acts. As these disciples of Jesus, who had recently wrongly been killed by the Jewish leaders, spoke the crowd that had gathered
"...Jews living in Jerusalem, devout men from every nation under heaven....were bewildered because each one of them was hearing them speak in his own language." They would have seen these "tongues of fire" and heard the message of repentance in their own native languages by men who did not speak those languages.
Peter spoke to these people with the power of God. After his message, the Jews "...were pierced to the heart, and said to Peter and the rest of the apostles, “Brethren, what shall we do?” Peter said to them, “Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit."
The timing of the event is no coincidence. The empowering of the Apostles was from God and it was obvious to the crowd.
"So then, those who had received his word were baptized; and that day there were added about three thousand souls. "
(Exodus 34, Acts 2)