When Christ told the disciples about His death, burial, and resurrection, they couldn't comprehend the lesson's ultimate meaning. Jesus, therefore, promised them that the Father would send the Comforter, the Holy Spirit, in His name to teach them all things and to remind them of everything He had said. This is a great comfort to the disciples because, unlike us, they don't have the Bible to turn to and look up whatever they need. They will, however, go to the ends of the earth, spreading the message about Jesus. So, it is important that the disciples know they have the facts of who Jesus was and what He said. It's also important for them to know that they are not going to be left without help. 
Thanks to the Holy Spirit, the disciples wrote the New Testament, which teaches us everything about Christ. It would be impossible for us to obey God's commands without the Holy Spirit enabling us to understand them. Therefore, for us today, the Holy Spirit enables us to understand, live out, and apply God’s Word in our lives.
Upon salvation, the Holy Spirit infused us, and we received a new heart. Whatever you are facing now, remember that the Holy Spirit is with you and within you. He will never leave you to face it alone.

Dear Heavenly Father, thank You for sending us the Holy Spirit in the name of our Lord, Jesus Christ, and having Him live within us so we are never alone. The fact that Your power resides in me gives me such comfort. In everything I do, may the Holy Spirit teach me, guide me, and show me Your will. It's my prayer that the Holy Spirit illuminates what I read in Your word so I can comprehend what I'm studying, not just for head knowledge but to get to know You better every day. 
In Jesus's name I pray. Amen.