With an open heart we can better learn the reason Jesus left this earth and the reason the Holy Spirit came to this earth to infill the church. Jesus spoke of the Holy Spirit in ways that would be helpful for us to keep in mind.
The Holy Spirit was sent by God to the first church established by Jesus on this earth. At the day of Pentecost, the Holy Spirit infilled those believers present in the upper room. Ever since then, whenever a person comes to Christ he also comes as a member of the building block of the church. Imagine a brick that is being used to build a church. One brick at a time is added. In the same way one believer is added as part of the church.
Jesus said the Holy Spirit would come upon them. This was especially important for the disciples because they had no New Testament needed the Holy Spirit to expound the truth from the Old Testament. Jesus said that the Holy Spirit would bring all things to our remembrance. This is especially important because we need to have a constant recollection of the work of Christ in our lives. Jesus also said that the Holy Spirit would give us the ability to bear witness of him.
Jesus said that we need to be aware of the work of the Holy Spirit toward the world. He said the Holy Spirit would reprove the world of sin and of righteousness. Finally, Jesus said the spirit of truth will guide us into all truth, including things to come. (John 16)
Take heart. Allow the Holy Spirit to work in your life. He will teach you and comfort you and guide you. He will help you to understand the word of God. The Holy Spirit would help you to realize and face things to come for this world.