The Holy Spirit of God!

Chapter 1

The Holy Spirit (God the Spirit)—Who Is He?
The Holy Spirit (God the Spirit) is one of the Three Persons of the Trinity—God the Father, God the Son, and God the Spirit. The Trinity (the Three Persons in one God) manifested itself during the baptism of Jesus Christ, the Son of God.

Now when all the people were baptized, and when Jesus also had been baptized and was praying, the heaven was opened, and the Holy Spirit descended upon him in bodily form, as a dove, and a voice came from heaven, “You are my beloved Son; with you I am well pleased.” (Luke 3:21–23 RSV)

Thus, during Jesus’s baptism, the Three Persons of the Trinity made their presence known. Jesus Christ Himself was one of them, the Holy Spirit as a dove was another one of them, and the voice from heaven was that of the Father Himself. For those who are in doubt of the Trinity, the event of Jesus’s baptism should settle the sceptics’ doubts.
The Holy Spirit is often referred to (by theologians and Bible scholars) as the Third Person of the Trinity, whereas God the Father is referred to as the First Person and Jesus Christ (God the Son) is the Second Person. These designations, as reasonable as they are, are not explicit in the scriptures; they are of human opinion, if you like, but they are derived (implicitly) from the promises and teachings of Jesus Christ Himself (the Second Person of the Trinity).

And I will ask the Father, he will give you another Counselor, to be with you for ever, even the Spirit of truth. (John 14:16–17 RSV)

Take note of the word “another.” Jesus speaks here of “another” (second) counsellor (besides the first), signifying that there was a previous (first) counsellor before this second one. And the first one was Jesus Himself. (The King James Version of the Bible calls the Holy Spirit “another Comforter.” Some other versions of the Bible call Him “another Advocate,” and others call Him “another Counselor.”) Whether He is another counsellor, another comforter, or another advocate, the word that stands out for us here (at this moment) is “another.” And Jesus identifies this “another” (second) counsellor as the Holy Spirit. Furthermore, Jesus is saying here, “I will ask the Father” (that is, by the Father’s permission). This implies that only the Father (the First Person of the Trinity) has the authority by which Jesus (the Second Person) can then send the Spirit (the Third Person) to His (Jesus’s) followers in the world. Then Jesus goes on to distinguish the Three Persons of the Trinity even more clearly.

When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. He [the Spirit] will glorify me [Jesus], for he will take what is mine and declare it to you. All that the Father has is mine; therefore, I said that he [the Spirit] will take what is mine and declare it to you. (John 16:13–15 RSV)

In order to understand a little better this deeply wonderful explanation (theology) revealed to us by Jesus, we will try to simplify the Trinitarian doctrine. God the Father (the First Person of the Trinity) is the Father of all, the Creator of all things seen and unseen; He is the seat of all authority. Jesus Christ (God the Son, the Second Person of the Trinity) is the first Son of the Father (firstborn—see Heb. 12:23; Col. 1:15 RSV); He is the Saviour of the world when the world yielded to evil and death. God the Spirit (the Holy Spirit and the Third Person of the Trinity) is like the second Son of God the Father. (If you like, the Holy Spirit is the younger brother of Jesus Christ.) In the book of Hebrews, we are informed, “But in these last days he [God the Father] has spoken to us by a Son, whom he appointed the heir of all things, through whom also he created the ages” (Heb. 1:2 RSV). Note the phrase “spoken to us by a Son.” It seems this implies God has another Son besides Jesus. Is the Holy Spirit the other Son? In Hebrew tradition (and probably in most traditions), the first Son is the inheritor, the heir, of the father’s inheritance or assets (and liabilities). He is next (second) to the father in authority. It appears this is what Jesus Christ is explaining to us here (see John 14:16–17, 16:13–15 RSV) about the relationships within the Trinity

And I will ask the Father, and he will give you another Counselor, to be with you for ever, even the Spirit of truth. (John 14:16–17 RSV)
When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, … he will glorify me, for he will take what is mine and declare it to you. All that the Father has is mine; therefore, I said that he [the Holy Spirit] will take what is mine and declare it to you. (John 16:13–15 RSV)

God the Spirit (the Holy Spirit) is the sanctifier and energiser of the creation—everything created. But again, it appears God the Father elevated God the Son and God the Spirit (beyond partnership or “sonship,” if you like) to an eternal existence; He made them divine just like Himself and made them equal with Himself, sharing His qualities and authority with the other two, making them one with Him. Jesus Himself said it at the time He was praying to God the Father for His followers.

All mine are yours, and yours are mine, and I am glorified in them. And now I am no more in the world, but they are in the world, and I am coming to you. Holy Father, keep them in your name, which you have given me, that they may be one, even as we are one. (John 17:10–11 RSV)
He continues.
That they may all be one; even as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me. The glory which you have given me I have given to them, that they may be one even as we are one, I in them and you in me, that they may become perfectly one, so that the world may know that you have sent me and have loved them even as you have loved me. (John 17:21–23 RSV)