BOOK: The Person and Ministry of the Holy Spirit
Chapter 1.4: Holy Spirit's Work

1.4    Holy Spirit's Work

The Holy Spirit's work in the earth can be simplified as transforming a person unto the image of Jesus Christ.  This includes rebirth, sanctification, grow, etc....  The unpardonable sin, against the Holy Spirit, is to totally stop once and for all this process of transformation.  This includes never receiving the blood of Jesus (rebirth) and dying in that state, or being born again and coming to a point of either refusing to take the blood of Jesus because of hardness of heart to stay in a continual sin, or because of being deceived by Satan that God will not forgive you, thereby allowing continual unbelief to prevent you from receiving the blood of Jesus.  In all cases, there is a continual sin1 that is not covered by the blood of Jesus, and an act of the will of the person to not receive the blood.
Hebrews   10:29
Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?
Without the blood, there remaineth no more sacrifice for sins2.3
The Holy Spirit will always lift Jesus up and bear witness of Him.
John 16:13-14
Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.  He shall glorify me: for he shall receive of mine, and shall shew it unto you.
You will notice that the Fruit of the Spirit in Gal 5:22-23 is singular, and the verb is is also singular.  The Holy Spirit's Fruit is our spirit being transformed into Jesus' image, which character traits are listed as love, joy, peace, ....

1. anything that is not of faith is sin, Rom 14:23
2. Heb 10:26-31, Heb 6:4-6
3. to the fact of falling from grace, see Gal 5:4, 2
Peter 1:10, 1 John 5:18, 2 Peter 3:17, Heb 4:11, Heb 12:15