Read Acts 2:1-21 with your family.
Pentecost (meaning “50 days” in Greek), was a festival for the Hebrew people where they celebrated the harvest of wheat, read the whole story of Ruth, remembered King David, and recognized the anniversary of Moses getting the 10 Commandments from Mount Sinai. It was an important time and the Hebrew people were expected to travel to Jerusalem to bring their offerings to the Temple.
That was the setting for the followers of Jesus, who were also there to celebrate Shavuot, the Hebrew name for this celebration. This time was different than any Shavuot celebrations in the past. This time the Holy Spirit, the presence of God that Jesus promised, came to the followers of Jesus.
They started talking in different language so all those from foreign countries heard the message of Jesus in their own words. This was overwhelming, and it was the start of what would eventually become the Christian religion. Pentecost is the birthday of Christianity.