The unity of the Father and the Son cannot be overstated. The scriptures fully capture the idea, but it is an idea that men cannot understand except it be by revelation from Heaven. You can say the words and never understand what is meant by them.
On the one hand, the Christian world is confused about the Godhead in that they believe the Father and the Son are the same being. They cannot grasp the reality of the nature of the Father and the Son. On the other hand, Mormonisms teachings on the Godhead have a tendency to lead its adherents to misapprehend the greatness of the unity of the Father and the Son. They are too separate in our minds and hearts. We cannot grasp the reality of the unity of the Father and the Son.
Overall, our emphasis in teaching that Christ is our spirit brother has diminished Him. He is the Lord God Almighty (2 Ne. 9:46). He is the Mighty God, the Lord God, and the Holy One of Israel (2 Ne. 9). We do not understand Him and our hearts are far removed from Him.
The unity we experience here on this earth is not like theirs, and cannot be compared unto it. The unity of those in Heaven is not to be learned from our experience here, though once it is learned from Heaven it may be sought after in our relationships on the earth.
The Book of Mormon is the place to begin seeking for understanding. The doctrine is clearly taught there, though it seems contradictory without divine teaching. If the unity of the Gods is manifest unto you, you will use the words of scripture to describe it; indeed, they are one God, yea, the very Eternal Father of Heaven and of earth (Mosiah 15:4).