Christian Scripture has always had to deal with what on the surface might seem like two contradictory propositions. On the one hand we have the idea that there is one Lord and God.
Hear, O Israel: The Lord our God is one Lord: 
On the other hand we have the idea that Jesus and the Father are two different persons or beings of some sort that are individual and distinct from each other.
For example, John 14:28:
Ye have heard how I said unto you, I go away, and come again unto you. If ye loved me, ye would rejoice, because I said, I ago unto the Father: for my Father is greater than I.
Thus we are presented with two simultaneous positions:
1) There is one God
2) That one God is made up of multiple persons/beings/individuals
The Bible addresses this oneness quite straightforwardly. We are told that Jesus and the Father are “one.”
My Father, which gave them me, is greater than all [note the assumption that Jesus and the Father are different people]; and no man is able to pluck them out of my Father’s hand. I and my Father are one.
The word “one” used in these verses is the Greek word “hen” rather than “hice.” Whereas “hice” would mean we are talking about one person, “hen” refers to some other types of oneness. Paul, trying to teach the early saints that it didn’t matter if they were converted to the Gospel by himself or Apollos, uses the same word “hen” to refer to a oneness of purpose to show that it didn’t matter who got the credit.
Now he that planteth [Paul] and he that watereth [Apollos] are one: and every man shall receive his own reward according to his own labour. For we are labourers together with God: ye are God’s husbandry, ye are God’s building.
The NIV makes this more clear:
“The man who plants and the man who waters have one purpose…”
Given that God’s oneness is not a oneness of person, it should not surprise us at all that Jesus freely intermixes His oneness with God and the disciples oneness with Himself:
And now I am no more in the world, but these are in the world, and I come to thee. Holy Father, keep through thine own name those whom thou hast given me, that they may be one, as we are.
The Book of Mormon’s Teachings On God’s “Oneness”
The Book of Mormon ups the ante on the doctrine of the “oneness of God.”
For starters, unliked the Bible, it leaves no doubt that Jesus, the Father, and the Holy Ghost are in fact one God, specifically calling them such.
Now, this restoration shall come to all, both old and young, both bond and free, both male and female, both the wicked and the righteous; and even there shall not so much as a hair of their heads be lost; but every thing shall be restored to its perfect frame, as it is now, or in the body, and shall be brought and be arraigned before the bar of Christ the Son, and God the Father, and the Holy Spirit, which is one Eternal God, to be judged according to their works, whether they be good or whether they be evil.
And they are one God, yea, the very Eternal Father of heaven and of earth. And thus the flesh becoming subject to the Spirit, or the Son to the Father, being one God, suffereth temptation, and yieldeth not to the temptation, but suffereth himself to be mocked, and scourged, and cast out, and disowned by his people.
Only the Book of Mormon uses such language to tell us that the oneness of the Father, the Son, and the Holy Ghost is that they are “one God.”
It is also clear to see that there is a strong sharing of titles with God. Jesus is the Father of heaven and earth just as much as the Father is. Jesus is the Eternal God (2 Nephi 26:12) but just as easily we speak of the Eternal God being someone different from Jesus (1 Nephi 12:18). Elsewhere Jesus is specifically called the Son of God (Mosiah 4:2). In Mosiah 3:8 we freely intermix titles emphasizing oneness while also separating the Father and the Son.
Mosiah 3:8 
And he shall be called Jesus Christ, the Son of God, the Father of heaven and earth, the Creator of all things from the beginning; and his mother shall be called Mary.
The oneness of God is emphasized a significant number of times in the Book of Mormon. By comparison their separateness, while definitely present (for one of the best examples, see 2 Nephi 31:11-12, 15 as was discussed in my previous post) is muted or downplayed in favor of God’s oneness.
This is one of the areas where I feel LDSism is different than the Gospel of Jesus Christ as taught in scripture. Our natural tendency as Mormons is to emphasize the separateness of the Father and the Son as this is seen as a defining difference between us and Orthodox Trinitarians. But God Himself consistently puts that emphasis in reverse.
In truth, we do not get a clear statement of God’s separateness in scripture until D&C 130:22 which is not until 1843, just before Joseph Smith’s martyrdom.
What I want to know is “why?” Why is the oneness of God so much more emphasized than God’s separateness? Why did God wait so long to reveal any more than that? Why did he reveal it only slowly? These are all questions worth pursing.
 I’ve pointed out elsewhere that this verse, in Hebrew, actually translates the word “one” from Echad rather than Ychid. Ychid means numerically one and Echad means one unity. So this verse actually leaves open the possibility that we are talking about more than one person or being, though it doesn’t state that definitively so.