Is a divine Person. Acts 5:3,4 Eph 4:30
Inspired the Scriptures. 2 Peter 1:20,21
Convicts the world of sin, and of righteousness, and of judgement. John 16:8
Sets us apart to God and enables us to believe the truth. 2 Thes 2:13
Gives us an understanding, so that we may know Him who is true. 1 John 5:20
Guides into all truth. John 16:13
Glorifies Christ John. 16:14
Teaches all things and brings them to mind. John 14:26
Enables us to obey the truth. 1 Peter 1:22
Brings about regeneration, or the new birth, through the word of God. Titus 3:5 1 Peter 1:23 John 3:5
Bears witness that we are children of God. Rom 8:16
Helps in our weaknesses and makes intercession for us. Rom 8:26
It is possible to resist the Holy Spirit Acts. 7:51

Heb 6:4-6 shows that it is possible to come very near the kingdom of God without entering in, and to "taste" of the things of Holy Spirit and yet never to have become a true child of God.