Today is referred to as Pentecost Sunday in Christianity. It is celebrated on the 50th day from Easter Sunday. It commemorates the outpouring of the Holy Spirit upon the Apostles and other followers of Jesus Christ while they were in Jerusalem celebrating the Feasts of Weeks as described in Acts 2. Based on our subject, we will answer three meaningful questions related to the Holy Spirit: (1) Who is the Holy Spirit? (2) What are Characteristics of the Holy Spirit? And (3) What does the Holy Spirit do?