The Holy Spirit is the 3rd Person of the Trinity, He also is eternal and fully God. He is the "Spirit of Truth" sent by the Father at the request of the Son (John 14-17). He is the Applier and Effector of salvation to believers. He is NOT just a force but is a person, our Teacher, Comforter, Reminder, Convictor, Guide and Intercessor. These are all profoundly personal acts, and the list of names describing Him could fill up pages.
He intercedes for believers (Romans 8:27); He knows the deepest things of God and reveals them (1 Corinthians 2:13); It is possible to grieve, lie to, and even insult the Holy Spirit (Ephesians 4:30, Acts 5:3 & 9, Hebrews 10:29, Isaiah 63:10). He speaks and instructs (Acts 8:29, 13:2), He gives spiritual gifts to the church as He determines (1 Corinthians 12:11).
The Holy Spirit acts in creation (Genesis 1:2), restrains sin in the world (Genesis 6:3), breathes out the Word of God (2 Timothy 3:16), and He works powerfully in the salvation and maturing of every Christian (John 3:5-7, Romans 8:1-16).
Who is the Holy Spirit to me personally and what does He do in my life?
Well, most could say that in certain situations they have been in they have been directed or felt a tug to go a certain way or have had peace in certain circumstances that they attribute to God. As they should, that is the Holy Spirit, the 3rd person of the Trinity.
That is the Holy Spirit!
He will bring you more peace and joy then you can imagine, as well as convictions when you start to go or are going in a direction away from the will of God.
See the Holy Spirit indwells us from the moment we turn our lives to Christ, we are a new creation. If we repent and truly seek God then the Holy Spirit guides and directs us, we will literally flow in the direction of Christ, being transformed and conformed to Him along the way. This brings peace and joy, it is now part of our DNA. But when we, as new creatures in Christ, start to turn and seek the world and the worldly things we will feel off, like we're going against the grain. Temporary joy comes leaving you shamed and confused.
That is the Holy Spirit: He leads, guides, turns and brings life and true joy because His purpose is to lead us to Christ as our Intercessor, whose purpose is to lead us to the Father as our Mediator.
Your Father has everything in His hands to make sure you find Him. All you have to do is answer His call, cry out to Christ and make Him your Lord and Savior, the Lord over your life, and you will be saved, indwelt with true life with the Holy Spirit.