The most important person on the face of the earth is the Holy Spirit.  The Holy Spirit has all knowledge, all wisdom and all power.  He is the one God sent to finish the work he started.
Who is the Holy Spirit?  How necessary is he?  Do we really need him?
The Holy Spirit is not an it, he is not a ghost floating around in the atmosphere, he is a person with a personality.  He is the third person of the Trinity, which is God the Father, God the Son and God the Holy Spirit.  In other scriptures in the bible, he is referred to as the Holy Ghost, but he is the same person.  He is also called the Spirit of Truth, he will guide us into all truth and show us things to come.  We need to understand his role and purpose in our lives.  The Holy Spirit is God.  He is the Spirit of God.  He's not a dove, he's not fire, wind or water.  The Holy Spirit is a person that carries a presence that you can see and feel.  He guides us to walk in the principles of God. 
Even before you received Jesus Christ as your Lord and Savior, he reproved you of your sins and told you to read your bible and go to church, or he sent someone to talk to you about God.  You didn't realize it was him, but he was wooing you.  He wanted you to know him.  The Holy Spirit was here before the world began.  In Genesis 1:1,2 it says, in the beginning God created the heavens and the earth and the earth was without form and void and darkness was upon the face of the deep and the Spirit of God moved upon the face of the waters.  He is a moving Spirit, he creates and makes things happen.  He speaks things into existence.  He created the sun, moon, stars and all the planets.
Gen 1:26 God said, let us make man in our image, after our likeness.  Who was the "us" and "our" God was referring to?  He was talking to the Holy Spirit and Jesus Christ, the second and third part of the trinity.  God is omnipresent- He is everywhere at the same time.  He is omniscient- He knows all things.  He is omnipotent- He is all powerful.  There is nothing he can't do, there is nothing too hard for him.  All things are possible for those who believe in him.  Now think about this for a minute, he is everywhere at the same time, he knows all things, there is nothing he can't do and he is all powerful.  Wouldn't you want somebody like him in your life?  The Holy Spirit will help you get solutions for every problem you have.  Why do we call our friends and family when we have a problem, they can't figure out how to solve their own problems.  We should talk to God first, he will lead us and guide us in the right direction and show us exactly what we need to do.
The Holy Spirit is our comforter, teacher, advocate, intercessor, helper, counselor, healer and our strength.  He cares about everything that concerns us.  He said he would never leave us or forsake us.
When Jesus resurrected from the dead, before he ascended up to heaven, he said he would send the comforter, who is the Holy Spirit to abide with us forever.  The life of a Christian should not be a struggle, if we yield ourselves to the Holy Spirit and allow him to lead us and guide us every day, we can live a victorious life.