Guest post by Hugh Fulford.
At one of my former churches, a mainline Christian church, I was surprised to discover that this basic understanding of the Holy Spirit was neither taught to nor commonly understood by the congregation. Since then this has proven to be the case with other mainline churches with which I come in contact. What you write about is an important topic.
The matter of "He" vs. "it" is a bit more nuanced than this. One of my earlier churches preferred "it", based upon the Greek of the NT. The word there is πνεῦμα and it is neuter, so technically they had a point. But "technical" isn't everything.
If one simply considers the unity of God, of Father, Son, and Spirit, the pronoun that makes sense for any of these words is "He", irrespective of grammatical gender. We don't routinely apply grammatical gender in this particular way to other names appearing in the NT.
What finally convinced me, however, is that there are verses to be found, such as John 16:8 that, in a different grammatical context where the head noun is not the neuter πνεῦμα but in this case the masculine παράκλητος (which we sometimes call the "Paraclete"), a masculine singular pronoun (ἐκεῖνος) appears in reference to the Spirit (Helper). So the text appears to simply observe good Greek grammar.
The problem I have is that I grew up in that particular earlier church, and the old habit lingers still. I do appreciate your reminder as to what the Word actually says.