Jesus is the central Being of all our three books, and the New Testament, and even, especially, the Old Testament which anticipates Him on every page in every feast and remembrance. Jesus is God. God is One. It is beyond our grasp to understand fully how Jesus was God in the flesh, both man and God, sent as Messiah (Christ), from God the Father, whose Being is uncontainable by either space or time. Yet God is One; the Scripture makes that clear.
Further there is yet another Person in the Godhead of One, namely that of the Holy Spirit. Jesus was sent by the Father, and is revealed by the Spirit. These are somehow Three in One–theologians use the term the Trinity–each God but not three Gods. Again, this is what is revealed to us, not something that we reason on our own from some first principle. We are created beings. We have been given certain capacities including reason but our inability to apprehend the essence of God should not surprise or distress us. Nor should we permit our reason, apart from revelation, be our authority of truth about God. Our reason, through the work of the Holy Spirit in the Scriptures can lead us to correctly understanding some things, actually many things, about God. But we, as finite, created beings are never going to fully understand the Being who is infinite and our Creator.
Let us consider here, below, what we can learn from the Gospel of John regarding this third Person of the Trinity, God the Holy Spirit. Our job here, is to observe, grasp, and cohere what has been revealed. It is actually the work of the Holy Spirit, through the Scriptures, that makes any such learning possible, and His primary task is revealing not Himself but the person and work of Jesus Christ. We will see this in the below verses where the references to the Holy Spirit are not primarily about the Holy Spirit but identification of His Being as the One who has revealed and will reveal Jesus Christ.
Gospel of John
Chapter 1
32
the Spirit descending; baptizes with the Holy Spirit
Chapter 3
6, 8
born of the Spirit (contrasted with born of the flest)
35
God does not give the Spirit sparingly
Chapter 4
23, 24
worship the Father in spirit and truth (2); God is spirit
Chapter 6
63
the Spirit is the one who gives life
Chapter 7
39
the Spirit, whom those who believed in him [Jesus] were going to receive, for the Spirit had not yet been given , because Jesus was not yet glorified
Chapter 14
16, 17
[the Father] will give you another Advocate to be with you forever; the Spirit of truth whom the world cannot accept
26
The Advocate, the Holy Spirit, whom the Father will send in my [Jesus] name
Chapter 15
26
When the Advocate comes, who I [Jesus] will send you from the Father—the Spirit of truth who goes out from the Father—he [the Spirit] will testify about me
Chapter 16
7, 8
For if I [Jesus ]do not go away, the Advocate will not come to you, but if I go, I will send him [the Spirit] to you. And when he [the Spirit] comes, he [the Spirit] will prove the world wrong
13
when he, the Spirit of truth, comes he [the Spirit] will guide you into all truth. For he [the Spirit] will not speak on his own authority, but will speak what he hears, and will tell you what is to come.
14
He [the Spirit] will glorify me [Jesus]
15
why I [Jesus] said the Spirit will receive from me what is mine and will tell it to you.
Chapter 20
22
he [Jesus, upon His resurrection] breathed on them and said “Receive the Holy Spirit.”