Second only to Easter, the feast of Pentecost must be understood in the context of the Jewish feast by the same name. Its other name in jewish tradition is Feast of Weeks, a full season of thanksgiving with Passover. This prolonged festival celebrated the theme of harvest and thanksgiving. It evolved before the time of Christ into a memorial of the covenant and, by 300 C.E., a memorial of the giving of the law.
Pentecost itself closes the Easter season. It celebrates the overwhelming experience of God pouring out the Spirit upon the first community of those who believed Jesus was the Lord and Christ (see Acts 2:1-4). Pentecost is called, therefore, the birth of the church's mission. The color of vestments and decorations for Pentecost is red. It symbolizes the intense love and fire of the Holy Spirit. Other symbols of the Pentecost event are the dove (see Luke 3:21-22), the tongues of flame (see Acts 2:1-4), and wind (see Acts 2:2).
[Source: Supplement, St. Paul Roman Catholic Cathedral, Saskatoon, SK, Canada; March, 2010]