What does the Holy Spirit do?
When Jesus was about to ascend into heaven, he said: "And I will ask the Father, and he will give you another Advocate to be with you always, the Spirit of truth, which the world cannot accept, because it neither sees nor knows it. But you know it, because it remains with you, and will be in you. I will not leave you orphans; I will come to you." -- The New American Bible (NABRE), 2011, John 14:16-18