A while back, KC Kern gave an explanation of the Mormon concept of Trinity. To summarize, Mormons often use the word “God” to refer collectively of the entire Godhead which can be thought of as an entity different but not fully distinct from each individual person in the Godhead. He likened “God” to a corporation, which is legally different from, but not fully distinct from the people that make up the corporation.
I think KC Kern’s explanation of the Mormon concept of Trinity is correct, but is missing (but hints at) one very important point which I wish to expand upon in the next few posts.
Included in the Mormon concept of deity is a doctrine called “Divine Investiture.” A summary of this doctrine is that each person in the Godhead fully represents the entire Godhead to the point of representing and even speaking for the others. 
Unfortunately Divine Investiture just doesn’t get the due it deserves. It is usually only trotted out to explain certain scriptures and then not mentioned again until we come to the next scripture that requires it. As such, some people have entirely discounted it as part of the doctrines of the LDS Church. They see it merely as an excuse to ignore or “figure-atize” scriptures that just don’t play well with Mormon’s (supposedly) otherwise Tritheistic doctrines. 
But if Divine Investiture is a doctrine of the Church — and we can’t deny that it is — and if our scriptures do indeed insist upon it, then the question we should be asking is “What is to be learned from this doctrine?”
Put another way, if the sole purpose of Divine Investiture is to explain away verses that teach nothing worthy of note, then the correct solution is to not have (or discount) those scriptures in the first place. But if those verses are in fact teaching something important in the doctrine of Divine Investiture, then we should take notice of them and seek what their message is.
The Significance of Divine Investiture
Divine Investiture means that every person in God (or the “Godhead” if you prefer ) fully represents the whole and also each other. It means that we can’t fully separate the persons of the Godhead. Note that this truth is decidedly at odds with the traditional Trinity doctrine where we aren’t supposed to confound the Persons of God (i.e. treats them as if they are the same person). In other words, Divine Investiture is one of the main differences (I’d argue, one of the very few or maybe only difference) between the traditional doctrine of Trinity and the Mormon form of it. Divine Investiture runs contrary to creed and tradition but not contrary to scripture, especially Mormon Scripture.
We sometimes liken Divine Investiture to the legal construct known as “power of attorney” and there are definitely some similarities, but this goes much deeper. Power of attorney merely means one person talks for another for legal purposes. Divine Investiture means they literally speak as if they were the other person, because in a sense, they are that other person.
In what sense are the members of the Godhead each other? The standard Mormon answer is that “they are one in purpose.” I find this answer correct, but misleading. The problem with the “one in purpose” wording is that it fails to capture that we are not talking about the members of the Godhead being one in a purpose but rather being one in all purposes.
Therefore, it might represent our beliefs better to say that we believe the Godhead to be one in that they share a single moral will and all purposes so deeply that they are a perfect oneness in every sense.
If this is correct, then we should not expect any other formula or doctrine for God to exceed the level of “oneness” that we are believing about God for ours is the penultimate level of oneness. 
Divine Investiture: The Lynchpin of Mormon Doctrine of Deity
Armed with this understanding, the real significance of Divine Investiture become clear; it is, in fact, the lynchpin of Mormon Doctrine of Deity. Remove it, and the rest falls rationally apart.
Craig Blomberg (in this previous post) was right about one thing, it is impossible to have more than one all-powerful “being” or rather, more than one all-powerful will.  That really is a contradiction. Blomberg thought he was attacking Mormonism with that comment, but he wasn’t. Mormons do believe in a single all-powerful will, so there is no contradiction. 
Ironically, Blomberg was inadvertently attacking his own Trinity doctrine because he was attacking the only logically feasible way to avoid turning Trinity into either a contradiction or Modalism.
Put another way, “Divine Investiture” is the same as “Oneness” which is the only possible logical foundation for both the Doctrines of Deification (i.e. humankind becoming Divine) as well as the plurality of gods (i.e. humankind joining the Godhead and the Persons of God (the Trinity swelling to Infinity.)
Divine Investiture is also the only possible logical foundation on which to build the doctrine of God once having been mortal (like Jesus was according to the Bible and the Father as well, according to Joseph Smith’s King Follett discourse) yet still be God. This means that hanging from this lynchpin is also the doctrine of theomorphic man (i.e. we are literally created in God’s image.)
Even God’s nature, love, charity, mercy, justice all are directly related to Divine Investiture. For it is impossible to imagine multiple perfect persons that don’t share a single will and thus, to some extent, a single identity. This means the concept of “God” as perfectly loving (or perfeclty merciful, or perfetly just) is impossible without the concept of “oneness” and thus is impossible without the concept of “divine investiture.”
Even the concept of the Priesthood is really the Doctrine of Divine Investiture in disguise; for what is Priesthood but mortals speaking as if they are God and thus, for that moment, being God? 
I simply cannot think of any Mormon Doctrine of Deity that doesn’t either lead to flow from Divine Investiture.
This is only the beginning of the explanation of why “Oneness” is emphasized over “Separateness” in the scriptures.
 Okay, I admit Divine Investiture is a bit more complex than that. There is a hierarchal element to it, such as Jesus represents the Father and the Holy Ghost represents both, and even that angels can represent Jesus, etc. But for our purposes, this hierarchal element neither strengths nor reduces the point I’m trying to make, so I’m leaving it out.
A full exposition on Divine Investiture is available in the classic article The Father and the Son: A Doctrinal Exposition by the First Presidency and the Quorum of the Twelve Apostles. This 1916 article is probably the original development of the Doctrine of Divine Investiture under that name.
 Skeptic Rick Grunder sent me a link to his own analysis of the Book of Mormon’s Doctrine of Deity where he concluced it was explicitly so-called Serial Modalism. In that paper, Rick gives a detailed analysis of the Mormon Doctrine of deity that entirely leaves out Divine Investitutre. He later mentions Divine Investiture in passing only to dismiss Givens’ analysis of it. Given this assumption, it is not suprising that he drew the conclusions he did. It is also not suprising that this analysis requires declaring by fiat all evidence to the contrary as figurative. How one reads the Book of Mormon Doctrine of Deity is a factor of whether or not they see Divine Investiture as a serious doctrine or one meant to explain things away.
 As discussed in this post, the word “God” has multiple meanings. One of those meanings is a synonym for the Godhead. KC Kern points out that such usage is common in the Church even if we don’t realize we speak in that way. It’s also noteworthy that in English “Godhead” means “The essential and divine nature of God, regarded abstractly” and that the Greek words translated to be “Godhead” in the New Testament all mean “Divinity” or “Godlike.” (See Strong’s 2304, 2305, 2320)
The only entity that has the unique Divine Nature (and is thus Godlike or Divine) is God. Thus Godhead was meant from the beginning to be a synonym for “God.” Mormons seem to have co-opted it as a word to refer to our “Trinity.”
 “If this is correct, then we should not expect any other formula or doctrine for God to exceed the level of ‘oneness’ that we are believing about God for ours is the penultimate level of oneness.” This means that all other Doctrines of Deity should, when analyzed, fall into three categories: 1) less oneness then the Mormon formula, 2) equivalent oneness to the Mormon formula, 3) No “oneness” at all, but just different names for a single thing. This last is because “oneness” implies real persons choosing to be “one” whereas “one atomic unit” might just be assigning two or more names to the same person/entity. In the strict sense, this is not “oneness” at all but just misleading wording. This seems like a good topic for a future post.
 To me, “Being” and “will” are the same. If you don’t prefer that way to think of the word, then I contend that you are actually just using it as a direct synonym of “person.”
 Ironically, Craig Bloomberg might well have been attacking some Menu Mormons, who sometimes believe in Deification, but not in Oneness, (i.e. That God will make us diverse gods) thus forming a logically contradictory doctrine out of two mutually exclusive beliefs.
Jesus’ argument (in John 10:35) is that someone that speaks for God through revelation is God (for that moment anyhow) and thus the title “gods” is appropriate. (i.e. “he called them gods unto whom the word of God came…”) So how could it be, Jesus asks, blaspheme for Him to claim to be one with the Father and thus God Himself? That’s what the scriptures they believed in already insisted upon (“the scriptures cannot be broken”). Thus Jesus explicitly linked the concept of Divine Authority (what today we call “Priesthood”) with His own Godhood. This deserves a post of it’s own, I suppose. Of course the Jews didn’t buy it and tried to stone him anyhow.
This also explains why part of the doctrine of Divine Investiture is that angels can speak as if they were Jesus who is, also by Divine Investiture, the Father.