The Holy Spirit is a “person” as described in the Bible.
The word "Holy" means pure or sacred. He is so important Jesus warns man that God regards His Life Giving Spirit to be so Holy and that no forgiveness can be expected should anyone speaks against Him and His work (Mark 3:28-30).
He is God's true witness to us (I John 4:6&9).
The Gospel (good news) is about receiving the Holy Spirit. "Unto whom it was revealed, that not unto themselves, but unto us they did minister the things, which are now reported unto you by them that have preached the gospel unto you with the Holy Ghost sent down from heaven; which things the angels desire to look into." (I Peter 1:12).
Jesus died for us so that we can receive the Holy Spirit (John 3:14,15, John 7:38,39; Luke 24: 49; Acts 1:4,5).
The Holy Spirit is God's Promise and Gift to us when we accept and obey the gospel of Jesus (Acts 2:38). When we receive the Spirit we receive the whole of God's 'packages' of blessings, signs, fruits and gifts. He does not give His Spirit by measure (John 3:34).
In fact, without the Holy Spirit one cannot belong to Christ (Romans 8:9).
He makes us holy. We receive His righteousness (I Peter 1:2, Romans 5:17,18; 8:10).
He is the means by which we are washed, regenerated, renewed or transformed from a sinner to be a child of God (Titus 3:5, Romans 8: 15).
When we receive Him we receive power from God to be His witnesses (Acts1:8). We are able to confirm what Jesus declared. As our understanding and faith grows, we allow the Holy Spirit to work through us (John 14:11-17).
He is our teacher. He gives us insights into God's love for us (John 16: 12-15; I Corinthians 2; 7-15). We were not capable of understanding God's love before we received the Holy Spirit (I John 4: 10,19; Romans 5:5). Through the Holy Spirit we actually experience the person of Jesus Christ (John 14:15-18; 16: 12-15; Ephesians 3:16-19).
He comforts us with God's peace (John 14:26,27). Peace is the absence of fear and uncertainty with God (John 14: 20,26,27). God offers certainty through personal confirmation when you receive the Holy Spirit with consistent evidence declared by Jesus.
We will personally know when the Holy Spirit comes to us (John 14: 15-20; Mark 16: 16-20; Acts 2:1-4, 32,33; 10:44-47). When we believe Jesus, He tells us that He will lead us to know the truth. He leads us by the signs listed in Mark 16:16 "He who believes and is baptized will be saved; but he who does not believe will be condemned. 17 And these signs will follow those who believe: In My name they will cast out demons; they will speak with new tongues; 18 they will take up serpents; and if they drink anything deadly, it will by no means hurt them; they will lay hands on the sick, and they will recover."19 So then, after the Lord had spoken to them, He was received up into heaven, and sat down at the right hand of God. 20 And they went out and preached everywhere, the Lord working with them and confirming the word through the accompanying signs. Amen".