Jesus Christ is Jehovahby David R. Seely
The Godhead consists of three separate and distinct beings: the Father, Son, and Holy Ghost (D&C 130:22; A of F 1). While some Christians do not equate Jesus Christ and Jehovah in their theologies, Biblical passages indicate that relationship, and Latter-day scriptures often refer to Jesus Christ, the Son, as Jehovah (e.g., D&C 110:3-4; Moro. 10:34).
The name Jehovah is an anglicized rendering of the tetragrammaton YHWH, a proper noun in biblical Hebrew that identifies God. Following a Jewish tradition that avoided pronouncing God's name, translators of the King James Version rendered almost all occurrences of YHWH as "Lord." Latter-day Saints view many other occurrences of "Lord" as references to Jehovah, both in the New Testament and in LDS scripture.
Since his premortal life, Jesus Christ has functioned as the constant associate of the Father working under his direction. In 1916 the First Presidency and the Quorum of the Twelve Apostles issued a doctrinal statement on the relationship between the Father and the Son: "Jesus the Son has represented and yet represents Elohim His Father in power and authority. This is true of Christ in His preexistent, antemortal, or unembodied state, in the which He was known as Jehovah; also during His embodiment in the flesh; and since that period in His resurrected state" (MFP 5:31-32).
Throughout scripture, several roles of Jehovah-Jesus Christ are specifically identified.
CREATOR. Jehovah as Creator is attested throughout the Old Testament (e.g., Ps. 24:1-2). Speaking to Moses, God said, "Worlds without number have I created; and by the Son I created them, which is mine Only Begotten" (Moses 1:33). John and others acknowledged Jesus as the Word, the Creator: "In the beginning was the Word; all things were made by him; and without him was not any thing made" (John 1:1-3, 14; cf. Eph. 3:9; Col. 1:16). Similarly, the Book of Mormon teaches, "The Lord Omnipotent who reigneth, who was, and is from all eternity to all eternity, shall come down from heaven among the children of men . 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" (Mosiah 3:5-8; cf. 2 Ne. 9:5; 3 Ne. 9:15).
LAWGIVER. To Moses, Jehovah identified himself by the title "I AM THAT I AM"a variation on the verbal root of YHWH (Ex. 3:14). This title was claimed by Jesus in mortality: "Before Abraham was, I am" (John 8:58; cf. John 4:26). After his resurrection, Jesus told hearers in the Americas, "Behold, I am he that gave the law, and I am he who covenanted with my people Israel; therefore, the law in me is fulfilled, for I have come to fulfil the law" (3 Ne. 15:5; cf. Matt. 5:17).
REDEEMER, DELIVERER, AND ADVOCATE. Jehovah delivered the children of Israel from Egypt. Paul taught that this same being would redeem mankind from sin and death (cf. 1 Cor. 10:1-4). This point is made clear in the Book of Mormon: "The God of our fathers, who were led out of Egypt, yea, the God of Abraham yieldeth himself as a man, into the hands of wicked men to be crucified" (1 Ne. 19:10; cf. 2 Ne. 9:1-26; Mosiah 13:33-35). When the Savior appeared to the Prophet Joseph Smith in the Kirtland Temple on April 3, 1836, "his voice was as the sound of the rushing of great waters, even the voice of Jehovah, saying: I am the first and the last; I am he who liveth, I am he who was slain; I am your advocate with the Father" (D&C 110:3-4).
JUDGE. The Book of Mormon prophet Moroni 2 drew attention to "the great Jehovah, the Eternal Judge" (Moro. 10:34), reaffirming what the Psalmist and others had said (e.g., Ps. 9:7-8; Isa. 33:22). Jesus Christ proclaimed that he was the judge: "For the Father hath committed all judgment unto the Son" (John 5:22, 27; cf. Acts 10:42).
IN HIS NAME. In the beginning, men began "to call upon the name of the Lord" (Gen. 4:25, 26; cf. Moses 5:8; 6:4). In Moses's time Jehovah instructed the priests to "put my name upon the children of Israel" (Num. 6:27; cf. Deut. 28:10). Before the coming of Christ, Book of Mormon people took upon themselves his name (Mosiah 5:8-12; Alma 34:38; see Jesus Christ, Taking the Name of Upon Oneself). In all dispensations, the name of Christ is the only name "whereby salvation can come unto the children of men" (Isa. 43:3, 11; Mosiah 3:17; Acts 4:12; cf. Moses 5:7-9).
Divine names and titles, especially in the Bible, are occasionally ambiguous. The distinction between the Father and the Son is sometimes unclear. For example, the Hebrew term elohima title usually applied to the Father by Latter-day Saintsoften refers to Jehovah in the Bible (e.g., Isa. 12:2). Furthermore, people prayed to Jehovah as if he were the Father. In some cases, ambiguity may be due to the transmission of the text; in others, it may be explained by divine investiture wherein Christ is given the authority of the Father: "Thus the Father placed His name upon the Son; and Jesus Christ spoke and ministered in and through the Father's name; and so far as power, authority, and Godship are concerned His words and acts were and are those of the Father" (MFP 5:32).
Talmage, James E. JC, pp. 32-41.