And, yet:
Luk 24:49 And behold, I am sending the promise of my Father upon you. But stay in the city until you are clothed with power from on high.” (ESV)
What is that promise that Jesus is sending?
Joh 14:16 And I will ask the Father, and he will give you
another Helper, to be with you forever,
Joh 14:17 even
the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him. You know him, for he dwells with you and will be in you. (ESV)
...
Joh 14:26 "But the
Helper, the Holy Spirit, whom the Father will send in My name, He
will teach you all things, and
bring to your remembrance all that I said to you." (ESV)
Joh 15:26 “But when
the Helper comes,
whom I will send to you from the Father,
the Spirit of truth,
who proceeds from the Father,
he will bear witness about me. (ESV)
Joh 16:7 Nevertheless, I tell you the truth: i
t is to your advantage that I go away, for if
I do not go away, the Helper will not come to you. But if I go, I will send him to you.
Joh 16:8 And when he comes,
he will convict the world concerning sin and righteousness and judgment:
Joh 16:9 concerning sin, because they do not believe in me;
Joh 16:10 concerning righteousness, because
I go to the Father, and you will see me no longer;
Joh 16:11 concerning judgment, because the ruler of this world is judged.
Joh 16:12 “I still have many things to say to you, but you cannot bear them now.
Joh 16:13 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.
Joh 16:14 He
will glorify me, for he
will take what is mine and declare it to you.
Joh 16:15 All that the Father has is mine; therefore I said that he will take what is
mine and declare it to you. (ESV)
The "Helper" is clearly the Holy Spirit, who is “another Helper.” That implies both that Jesus is the first “Helper” and that the Holy Spirit is one who is like him but distinct from him. That is the plain reading of the text and it implies personhood. For example, if I'm at someone's house and have a piece of cake for dessert, which I eat, and then am asked if I want another piece, I fully expect to get a different piece of the same cake, unless some further qualification is made.
And, what is a "Helper"? When we look at the Greek, it is the word
parakletos, which means not only "helper, counselor, comforter, advocate;" all of which either are or can be actions of persons. The meaning of advocate is important since persons advocate on behalf of other persons; "its" cannot advocate for anyone or anything.
Pay close attention to the actions of this other Helper: teaches; brings things to remembrance; testifies; convicts. These are actions of personal agency, not an "it." And, Jesus says it is for their advantage that he leaves and sends this Advocate. How is it, then, that having an "it" would be to their advantage? Could a chair, rock, or impersonal power do any of these things or be of an advantage when Jesus left?
Parakletos is used only five times in the NT. In addition to the above four instances in John, the fifth is also by John here, for "advocate":
1Jn 2:1 My little children, I am writing these things to you so that you may not sin. But if anyone does sin, we have an
advocate with the Father, Jesus Christ the righteous. (ESV)
Jesus is said, by John, to be an advocate. It is not insignificant, then, that John records Jesus saying that he will send "another
parakletos." Jesus was the first
parakletos, and remains so, but in John’s gospel he was returning to the Father and the disciples still needed much help and guidance. It all points to the Spirit being a person and also being truly God, in the same way Jesus is truly God.
An advocate
can only be a person. Here is how parakletos is defined:
NAS Word Usage - Total: 5
1. summoned, called to one's side, esp. called to one's aid
1. one who pleads another's cause before a judge, a pleader, counsel for defense, legal assistant, an advocate
2. one who pleads another's cause with one, an intercessor
1. of Christ in his exaltation at God's right hand, pleading with God the Father for the pardon of our sins
3. in the widest sense, a helper, succourer, aider, assistant
1. of the Holy Spirit destined to take the place of Christ with the apostles (after his ascension to the Father), to lead them to a deeper knowledge of the gospel truth, and give them divine strength needed to enable them to undergo trials and persecutions on behalf of the divine kingdom
https://www.biblestudytools.com/lexicons/greek/nas/parakletos.html]
It's strongly implied that the Holy Spirit is a person, and so it can only be that he is also truly God, the same as the Father and as the Son.
Matt 12:31-32--blaspheming the Holy Spirit is an eternal sin, while blasphemy against Jesus is not. It's hard to understand how, according to your position, blaspheming a non-person is a greater sin than blaspheming a person (the Son of God no less).
Matt 28:19--singular name, three persons, one God.
Interestingly, the Holy Spirit is not only referred to as the Spirit of God, but also the Spirit of Christ or the Son or Jesus (Acts 16:6-7; Rom 8:9; Gal 4:6; Phil 1:19; 1 Pet 1:11). This shows the nearness and intimacy of the three persons.
The Holy Spirit:
Acts: Matt 4:1; Acts 8:39, 16:7
Listens: John 16:13
Speaks: John 16:13-15; Acts 1:16, 10:19, 11:12, 11:28, 13:2, 15:28; 1 Tim 4:1; Heb 3:7
Can be lied to: Acts 5:3, which is the same as lying to God (5:9)
Bears witness: Rom 8:16; Heb 10:15; 1 John 5:6
Helps, intercedes, and searches: John 14:16, 15:26, 16:7; Rom 8:26-27; 1 Cor 2:10
Teaches: Luke 12:12; John 16:13; 1 Cor 2:13
Gives gifts: Acts 20:28; 1 Cor 12:11; Heb 2:4
Leads: John 16:13; Gal 5:18, Heb 9:8
Can be grieved: Eph 4:30
Can be outraged: Heb 10:29
Can be blasphemed: Matt 12:31-32
Convicts: John 16:8-11
These are all actions of personal agency. And on it goes.
Given the above, I would say that since we know the Father and the Son are distinct persons yet both truly God, it necessarily follows that the Holy Spirit is a distinct person that is also truly God. And since know there is only God, the Trinity is the best explanation.