Veni, Sancte Spiritus! Come Holy Spirit, fill the hearts of your faithful, and kindle in them the fire of your love! The pouring of the Holy Spirit at Pentecost crowns God’s Salvation Plan and commemorates the birth of the new people of God, the Church.
A large number of devout Jews had come to Jerusalem, as required by the custom, to celebrate the Feast of Weeks, also called Shavout or Pentecost. This feast, celebrated fifty days after Easter, commemorates the moment in which the people of Israel received the Ten Commandments after having experienced God's saving action freeing them from Egypt.
Pope Francis gave a very vivid description of that day in his Homily for Pentecost last year:
“But what happened on that day, so distant from us and yet so close as to touch the very depths of our hearts? Luke gives us the answer in the passage of the Acts of the Apostles which we have heard (2:1-11). The evangelist brings us back to Jerusalem, to the Upper Room where the apostles were gathered. The first element which draws our attention is the sound which suddenly came from heaven “like a strong driving wind”, and filled the house; then the “tongues as of fire” which divided and came to rest on each of the apostles. Sound and tongues of fire: these are clear, concrete signs which touch the apostles not only from without but also within: deep in their minds and hearts. As a result, all of them "were filled with the Holy Spirit”, who unleashed his irresistible power with amazing consequences: they all “began to speak in different languages, as the Spirit gave them ability”. A completely unexpected scene opens up before our eyes: a great crowd gathers, astonished because each one heard the apostles speaking in his own language. They all experience something new, something which had never happened before: “We hear them speaking in our own tongues”. And what is it that they are they speaking about? “The mighty acts of God”.”
The same Spirit that was sweeping over the waters in the beginning, the same breath of life that God blew into his creation to give it life, the same spirit that accompanied the people of Israel during their journey through the desert, the same spirit who spoke for the prophets, the same spirit that came upon Mary when she conceived, was now inaugurating the new creation of God and the new covenant through his son Jesus Christ.