Eleven days before his death, Joseph Smith taught, “I have always declared God to be a distinct personage, Jesus Christ a separate and distinct personage from God the Father, and that the Holy Ghost was a distinct personage and a Spirit” (see also D&C 130:22). 29 There are three distinct persons in the Godhead. The Prophet also declared, “Everlasting covenant was made between three personages before the organization of this earth, and relates to their dispensation of things to men on the earth. These personages … are called God the first, the Creator; God the second, the Redeemer; and God the third, the Witness or Testator.” 30
The Book of Mormon teaches plainly the roles of the second member of the Godhead as the Old Testament Jehovah and the New Testament Jesus, but it also plainly elucidates his roles as Father and Son.
Jesus Christ is both the Son and the Father—the Son because he was begotten by God the Father and submitted to the will of the Father, but also the Father in the sense that he is the creator or father of the earth; he is the father of our flesh because our flesh is made from the dust or elements of the earth that he created; he is the God or Father of the Old Testament and the Father or Author of our salvation; he was and is the great Jehovah; he has all the attributes of the Father; and by divine investiture he serves the role of the Father in all things relative to our salvation. By his sacrifice, he became even more than our Savior—he became our covenant Father, and as we are spiritually reborn we become the children of Christ (for further references and explanation about becoming sons and daughters of Christ, see Mosiah 5:7; 27:25; Ether 3:14; D&C 25:1; 34:3; 39:4). The foregoing is a summary of a statement issued in 1916, “The Father and the Son: A Doctrinal Exposition by the First Presidency and the Twelve.”
Jehovah of the Old Testament and Jesus of the New Testament are explained and distinguished. The phrase “they are one God” in verse 4 refers to Jehovah and Jesus as one God—the same Person.
In addition, all of the Gods constituting the Godhead are one God in the sense that they are of exactly the same mind and heart in everything they do with us here on earth. The concept of unity or oneness is foundational in the gospel of Jesus Christ. It is the basic and essential message inherent in the otherwise abstract English word atonement, “at-one-ment,” or the idea of becoming one. So much alike are the three members of the Godhead that if we know one, we know the others. The Father, the Son, and the Holy Ghost are one God (2 Nephi 31:21; Alma 11:44; 3 Nephi 11:36; D&C 20:28). 31
Brigham Young University professors Stephen Robinson and Dean Garrett clarify: “We tend to focus on the distinctions between the Father, Son, and Holy Ghost in order to understand them as individuals. But the message of [D&C 93:3: ‘I am in the Father, and the Father in me, and the Father and I are one’] is that such a neat division between their respective roles is sometimes difficult to make—for their complete unity of thought, personality, and purpose usually makes them better understood by their oneness, by their ‘alikeness,’ than by their differences. This unity of the Godhead is so perfect that it sometimes confuses us, as when Christ speaks as the Father, or when the Holy Ghost speaks as the Son (see Moses 1:6; 5:9; D&C 29:1, 42). As we teach the truth concerning the separate physical natures of the Father and the Son, we must be careful not to separate them in any other sense, for the Father and the Son are ‘in’ each other (John 14:10) and are one in a way difficult for mortals to fully appreciate, though in a way that does not compromise their separate and individual being.” 32
Mosiah 15:5–9 describes in considerable detail Christ’s perfect willingness to come down and perform mighty miracles and yet experience rejection, suffering, and death, all according to the will of the Father, to intercede for all the children of men and resolve all the consequences of the Fall. Thus, Jesus the Messiah is the great Mediator (see D&C 76:69). He pleads our case before God the Father (see D&C 45:3–5). See commentary at 2 Nephi 2:8–10 and the accompanying chart.