Matthew Paulson wrote the following on the Holy Spirit in Latter-day Saint theology:
In Mormonism, the Holy Spirit is a “personage of Spirit.” It is problematic for Mormons to explain how the Holy Spirit became God without a human form. (Matthew A. Paulson, Breaking the Mormon Code: A Critique of Mormon Scholarship Regarding Classical Christian Theology and the Book of Mormon [Livermore, Calif.: WingSpan Press, 2006, 2009], 69 n. 229)
Elsewhere, he noted:
[I]n LDS theology the Holy Spirit is a disembodied “personage of Spirit,” (D&C 130:22). Is the Holy Spirit to be pitied? (Ibid., 86)
There are many problems with such arguments. Firstly, while the Holy Spirit does not have a human body, it is wrong to claim that he is “without a human form”; indeed, Latter-day Saint Scripture clearly presents the Holy Spirit as having a human form,
And it came to pass after I had seen the tree, I said unto the Spirit: I behold thou hast shown unto me the tree which is precious above all. And he said unto me: What desirest thou? And I said unto him: To know the interpretation thereof-- for I spake unto him as a man speaketh; for I beheld that he was in the form of a man; yet nevertheless, I knew that it was the Spirit of the Lord; and he spake unto me as a man speaketh with another. (1 Nephi 11:9-11, emphasis added; cf. see David Bokovoy, “Thou Knowest That I Believe”: Invoking The Spirit of the Lord as Council Witness in 1 Nephi 11)
Furthermore, in LDS theology, there is no such thing as immaterial spirit; even "spirit" in LDS theology is "material"; as we read in D&C 131:7:
There is no such thing as immaterial matter. All spirit is matter, but it is more fine or pure, and can only be discerned by purer eyes.
As for the divine status of the Holy Spirit, John Tvedtnes cogently noted that:
Latter-day Saints have no problem accepting that Christ and the Holy Ghost were already Gods without having taken a body. Nowhere do the scriptures indicate that this is not possible, only that it is not the case for us. If one considers that there are qualitative differences between us and all of the members of the Godhead, there is no problem of logic.
For more on the Holy Ghost, see, for example, these entries from The Encyclopedia of Mormonism:
