The Most Important Thing about the Holy Spirit

Jesus is leaving. The disciples are scared. Soon, they'll be hiding in a room, cowering in fear. They'd give anything to have him in the room with them. Sometimes, we know the feeling. What do we do when we're too scared to act? Too scared to witness? To scared to stand for truth? Jesus said that it is 'for our good' that he leaves. How can this be? And how can we be more courageous?