Acts 2:1-4 (NRSV)
“When the day of Pentecost had come, they were all together in one place. And suddenly from heaven there came a sound like the rush of a violent wind, and it filled the entire house where they were sitting. Divided tongues, as of fire, appeared among them, and a tongue rested on each of them. All of them were filled with the Holy Spirit and began to speak in other languages, as the Spirit gave them ability.” 

Many words and images come to mind when I think of Pentecost and the Holy Spirit. The Holy Spirit, also called the Holy Comforter or advocate, is the Person of the Trinity I call upon when I am scared or need comfort. But on the Day of Pentecost, fifty days after Easter, the Holy Spirit seems less like a Comforter and more like a divine explosion, tsunami, or Discomforter. The wild, untamable Spirit of God propels the disciples and people in Jerusalem to actions and speech out of their control. Pentecost is called the birthday of the Church because on this day God anoints and commissions individuals to spread the Good News of Jesus as a community and to go places where they would not dare to go on their own. Celebrations of this Birthday on Pentecost Sunday include symbols of wind, fire, the Dove, and the color red.

Perhaps an apt blessing for this Pentecost Sunday is from Romans 15:13 (NIV)
“May the God of hope fill you with all joy and peace as you trust in him, so that you may overflow with hope by the power of the Holy Spirit.”