Almost 2,000 years ago, a miraculous, momentous event occurred—the New Testament Church was founded on the Feast of Pentecost. What made this event so astounding—and Acts 2 records that the circumstances of that day were truly dramatic—was the giving of God's Holy Spirit to the followers of Jesus Christ, just as He had promised. What is this Holy Spirit that came on Jesus' followers that day? Why did these things happen? What should we learn from those strange occurrences? Even more importantly, what role does God's Holy Spirit have in a Christian's life? To understand this topic, we must first understand what the Holy Spirit is and what it is not. To grasp that, we must understand what the Holy Spirit does in a Christian's life. What does the Bible teach about the Holy Spirit? The answer to this question holds the truth of the amazing future God has in store for every human being. We'll see that God's Holy Spirit is the catalyst in a transformed Christian life.