The Spirit of the Lord fills the whole world, and holds all things together
and knows every word spoken by man, Alleluia.
Wisdom 1:7
The Church celebrates Pentecost (so called because it is fifty days after Easter Day) as the day on which the Holy Spirit descended upon the apostles, gathered in an upper room with Mary, mother of Jesus, "as a mighty, rushing wind", fulfilling Jesus' promise when he "breathed on them", as recorded in John's Gospel (chapter 20).
This event, which marks the beginning of the Church, is recorded in the book of Acts of the Apostles, chapter 2. The 14th century Siennese painting by Duccio illustrates the moment when the Bible says the Spirit descended upon the gathering of Christians in the form of tongues of fire. The liturgical color for Pentecost is red, a reminder of the flames that "rested on them". Another symbol for the Holy Spirit is the dove, usually emmitting golden rays of light.
The Holy Spirit gave the apostles gifts of grace through which they would undertake the evangelical mission of the Church. On the day of Pentecost, the apostles were given the miraculous "gift of tongues" -- so that everyone from every country understood the Christians inspired message of salvation as if the they were hearing it in their own languages. Thousands were converted by the preaching of Peter and the other apostles.
Called Whitsunday (white Sunday) in England, for the white garments worn by confirmands (candidates for Confirmation), Pentecost, or the Feast of Weeks, originated as a Jewish festival fifty days (seven weeks) after Passover.
The Solemnity of Pentecost ends the Easter season. After Pentecost, the Easter candle is kept in the baptistery or near the baptismal font, and is lighted only for a baptism. For centuries, the Sundays of the Catholic Church year between Pentecost and Advent were numbered as "after Pentecost". Since the Second Vatican Council, this period is called "Ordinary Time" (the first period of Ordinary Time is that between the Epiphany and Lent). Three Solemnities are celebrated in the weeks immediately following Pentecost: Trinity Sunday, Corpus Christi (The Body and Blood of Christ) and the Sacred Heart of Jesus.
Source: http://www.wf-f.org/Pentecost.html
