You just validated part of my point that scripture isn’t as clear about the Trinity as many grew up believing it to be. If the three are co-equals, why are only two given divine titles, worshiped and prayed to but not the third member? That was answered, and as cited, "the Lord is that Spirit." (2Cor. 3:17)
.. And the referent for "that Spirit" appears to be here:
2Co 3:2-3 Ye are our epistle written in our hearts, known and read of all men: (3) Forasmuch as ye are manifestly declared to be the epistle of Christ ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshy tables of the heart.
... so that in the discussion that follows Paul is unfolding how the Holy Spirit works in the heart to remove the "veil of Moses" and turn the believer from the dead letter of the Old Covenant to the fullness of spiritual life in Christ. And if that Spirit is the Lord, per verse 17, it is inescapably clear that the Holy Spirit and God are being treated here as one and the same divine Being.
Which gets us on to the question of clarity. The above passage is just one of many that establish the unique divinity and personality of the Holy Spirit. The notion that there must be some one passage that sets it out all in one place for one-stop shopping convenience is perhaps a reflection of modern consumer expectations, but in dealing with eternal truth concerning the divine nature, it is an absurdity, and itself an unscriptural idea:
Pro 25:2 It is the glory of God to conceal a thing: but the honour of kings is to search out a matter.
God is not obligated to make it so nor has he stated anywhere that all spiritual truth will be obvious and easy. Indeed, Paul makes the case that there are levels of difficulty, which he distinguishes as "milk" doctrines versus "meat" doctrines:
Heb 5:12-14 For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat. (13) For every one that useth milk is unskilful in the word of righteousness: for he is a babe. (14) But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil.
We do hold those doctrines necessary for salvation to be sufficiently clear that lost sinners are both accountable for their rejection of them and also may come to salvation through them, according to the grace of God. But that does not make those more challenging truths less true, nor less essential to the body of truth "once delivered to the saints." Thus, as Daniel says, we are obligated to believe them once they have been shown to us, and rejection of them is either a retardant to our spiritual growth or an indicator of a deeper unbelief.
But as a matter of clarity, I think it is only by the most obscure sophistry that one can conclude the Holy Spirit is created, rather than uncreated and eternally divine. As Daniel has already (and very clearly I might add) shown how the Holy Spirit is in consistently ascribed the qualities of divinity and personality, the burden shifts to would-be Arians to show He was in fact created. In other words, if you really want clarity in a single passage, you would need to have some passage that clearly and unambiguously showed that, despite 1Cor 3:17 and many other such passages, there was a moment of beginning for the Holy Spirit, a time or at least a circumstance when He did not exist. Can you show such a passage? I say you cannot.
Now I am familiar with the attempt of some to draw a connection between the creation of the "wind" (somewhere in Amos, I think) and the creation of the Spirit. However, the wind, as a created thing, is used in analogy to Spirit. It is not the same thing as the Spirit. You cannot, for example, argue from the limitations of a door, that those limitations apply to Jesus. The analogy is used for its ability to help us understand, however poorly, some aspect of the divine person of the Spirit, but not to limit the Spirit to the physical limitations of the metaphor.
As for the notion of agency, we would expect God the Son to act in agency of God the Father, but with no inference against their being, in essence, the same divine Being. Likewise with the Holy Spirit. If indeed there are three persons of one being, acts and representations in agency would be exactly what we should expect to see among them. How else could it be? Unless one wanted to argue for disagreement in the Godhead, which would be unthinkable.
In any event, the fact that these truth aren't set up in five or so easy bullet points in a single passage is actually a comfort to me that they are more like true things than false things. CS Lewis spoke about this once. Don't remember the exact quote. But it was one of the things that shook him out of his atheism. Mere mortals wanting to teach some invented religious "truths" would package them for easy dispensing to the "devoted." Real things are messier. They just are. You encounter them as they unfold in space and time. It's not all neatly packaged and designed for mass consumption. It is just one real thing that happens, and then another, and another, and you eventually begin to get the drift that the whole God-man thing doesn't seem like a concocted story after all, but something emerging naturally and inescapably from a reality that surprised you, as real things always do.
Peace,
SR