Today, we celebrate Pentecost.

When the day of Pentecost came, they were all together in one place. Suddenly a sound like the blowing of a violent wind came from heaven and filled the whole house where they were sitting. They saw what seemed to be tongues of fire that separated and came to rest on each of them. All of them were filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them. Acts 2:1-4 (NIV)

Peter explains, according to the prophet Joel:

In the last days, God says,
I will pour out my Spirit on all people.
Your sons and daughters will prophesy,
your young men will see visions,
your old men will dream dreams.
Even on my servants, both men and women,
I will pour out my Spirit in those days,
and they will prophesy.
I will show wonders in the heavens above
and signs on the earth below,
blood and fire and billows of smoke.
The sun will be turned to darkness
and the moon to blood
before the coming of the great and glorious day of the Lord.
And everyone who calls
on the name of the Lord will be saved.  Acts 2:17-21 (NIV)

Passage: Acts 2:1-21