A recent comment published in the New York Times by presidential hopeful Mike Huckabee brought up the issue, are Jesus and Satan brothers? The interviewer writes:
I asked Huckabee, who describes himself as the only Republican candidate with a degree in theology, if he considered Mormonism a cult or a religion. ‘I think it’s a religion,’ he said. ‘I really don’t know much about it.’ I was about to jot down this piece of boilerplate when Huckabee surprised me with a question of his own: ‘Don’t Mormons,’ he asked in an innocent voice, ‘believe that Jesus and the devil are brothers?’ (“The Huckabee Factor“)
Huckabee’s not-so-innocent statement (not question) was intended to create animosity towards Mitt Romney’s religion—towards Mormonism. So what is the story behind the statement, “Don’t Mormons believe that Jesus and the devil are brothers?” Huckabee is not the first to mention it. I came across it a few times while serving my two years as an LDS missionary.
The answer to the question “Are Satan and Jesus brothers?” is best placed in the context of the premortal existence.
Mormons believe that before the earth was created we existed as spirit children of our Heavenly Father. This existence is called the premortal existence, or the pre-existence–I’ll call it premortality., Jesus was among these children; as well as you, me, and everybody else–including Lucifer. During this existence we learned, progressed, and developed. Then finally the time came for us to progress to the next stage of existence–mortality. Our Heavenly Father gathered us together and proposed what we call the plan of salvation. “We will go down, for there is space there, and we will take of these materials, and we will make an earth whereon these may dwell; And we will prove them herewith, to see if they will do all things whatsoever the Lord their God shall command them,” are the basics of the plan (Abr. 3:24-25). It was further decided that since committing sin was going to be unavoidable a savior must be provided. So the Father said, “Whom shall I send?” And two persons came forward, “One answered like unto the Son of Man: Here am I, send me. And another answered and said: Here am I, send me. And the Lord said: I will send the first. And the second was angry, and kept not his first estate; and, at that day, many followed after him” (Abr. 3:27-28). The first, who was “like unto the Son of Man,” was Jesus. The second was Lucifer. The difference between them is that Jesus is always the obedient son: “But, behold, my Beloved Son, which was my Beloved and Chosen from the beginning, said unto me–Father, thy will be done, and the glory be thine forever” (Moses 4:2). However, Lucifer wanted to alter the Father’s plan so as to guarantee salvation for all mankind, but at the expense of personal agency:
[Lucifer] came before me [the Father], saying–Behold, here am I, send me, I will be thy son, and I will redeem all mankind, that one soul shall not be lost, and surely I will do it; wherefore give me thine honor… Wherefore, because that Satan rebelled against me, and sought to destroy the agency of man…and also, that I should give unto him mine own power; by the power of mine Only Begotten, I caused that he should be cast down; And he became Satan, yea, even the devil, the father of all lies, to deceive and to blind men, and to lead them captive at his will, even as many as would not hearken unto my voice. (Moses 4:1-3).
So in the Mormon view the Devil and his angels are simply the cast out, and fallen, spirit children of our Heavenly Father.
What do the scriptures say?
It is in that light that we interpret the following passages of scripture.
Isaiah 14:12-15: How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations! For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north: I will ascend above the heights of the clouds; I will be like the most High. Yet thou shalt be brought down to hell, to the sides of the pit.
Luke 10:18: And he said unto them, I beheld Satan as lightning fall from heaven.
Revelation 12:7-9: And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels, And prevailed not; neither was their place found any more in heaven. And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
And from LDS scripture:
An angel of God who was in authority in the presence of God, who rebelled against the Only Begotten Son whom the Father loved and who was in the bosom of the Father, was thrust down from the presence of God and the Son, And was called Perdition, for the heavens wept over him–he was Lucifer, a son of the morning. (D&C 76:25-26)
So are Jesus and Satan brothers? Well, they were both created by God the Father, so I suppose in that sense they are. And in that sense everyone are brothers and sisters. Also, it is not uncommon for Mormons to refer to Jesus as our elder brother. So the evangelical accusation that we believe Satan and Jesus are brothers is not without foundation. What bothers me about what they say is they carefully avoid anything that would provide context to LDS beliefs. Also, a proper response is difficult because explaining context is often laborious, even tedious. As such, it is hardly an effective response to an accusation that takes less than a second to make. On the other hand we can’t respond with “No, that’s not true.”
The LDS Newsroom handled it in this way:
Like other Christians, we believe Jesus is the divine Son of God. Satan is a fallen angel.
As the Apostle Paul wrote, God is the Father of all. That means that all beings were created by God and are His spirit children. Christ, however, was the only begotten in the flesh, and we worship Him as the Son of God and the Savior of mankind. (“Answering Media Questions about Jesus and Satan“)
The above statement is an appropriately short response to a short criticism. Though it doesn’t mention premortality it should be remembered that it is designed to address fears people might have about Mormonism: fears that we might believe Jesus and Satan are in collusion; or that we believe in a kind of dualism where good and evil are equal partners; or that Satan is Jesus’ equal; or that we don’t worship Jesus.
 The premortal existence is also called the first estate. The mortal existence is called the second estate. So we interpret “And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day” (Jude 1:6).
The ESV reads, “the angels who did not stay within their own position of authority”.
The NASB reads, “angels who did not keep their own domain, but abandoned their proper abode”
And the ALT reads, “angels, the ones not having kept their own domain, _but_ having left their own habitation”
 The second estate is mortality. Thus,
they who keep their first estate [i.e. are faithful in premortality] shall be added upon [i.e. born to mortality]; and they who keep not their first estate shall not have glory in the same kingdom with those who keep their first estate; and they who keep their second estate [i.e. are faithful in mortality] shall have glory added upon their heads for ever and ever. (Abr. 3:25-26)
 In the Mormon view, because the Devil and his angels were in the premortal existence they recognized Jesus when they saw him.
there met him two possessed with devils, coming out of the tombs, exceeding fierce, so that no man might pass by that way. And, behold, they cried out, saying, What have we to do with thee, Jesus, thou Son of God? art thou come hither to torment us before the time? (Matt. 8:28-29)
And there was in their synagogue a man with an unclean spirit; and he cried out, Saying, Let us alone; what have we to do with thee, thou Jesus of Nazareth? art thou come to destroy us? I know thee who thou art, the Holy One of God. (Mark 1:23-24)
And because they were denied their second estate they desire to have a physical body and if they can they will possess the bodes of men. (See. Matt. 12:43-44; Mark 1:23-26; Mark 3:11; Mark 5:1-15.) And if not human bodies then they settle for something else.
So the devils besought him, saying, If thou cast us out, suffer us to go away into the herd of swine. (Matt. 8:31)
 Apostle (and eventual President of the Church) Joseph Fielding Smith wrote:
We are taught that we are all children of God; he is our Eternal Father. By that we mean that he is the Father of our spirits, and that Jesus Christ is our Elder (Oldest) Brother–the Firstborn Son of God in the Spirit and the Only Begotten Son of God in the flesh. For an untold period of time we dwelt in the presence of our Father, and there we walked by sight. We saw him as a glorious being with a body that shone with the brilliance like the sun. He had a body of flesh and bones–a tabernacle for his Spirit. We were spirits only, so was Jesus. As spirits, dwelling in that first estate, it was impossible for us to obtain a fullness of joy. We could not advance to receive the blessings which our Father had in store for his children in that estate. It was the will of our Father that we have the opportunities of a second estate where we would receive bodies of flesh and bones as tabernacles for our spirits.
This was not all. It was necessary also that we pass through a period of mortality where we would be required to walk by faith and be shut out of the presence of our Father. (Answers to Gospel Questions, p. 212)
 It should be pointed out that in LDS beliefs angels are men. Usually resurrected, but not always, whom God sends as messengers. For example, in the LDS view Michael the archangel and Gabriel are Adam and Noah respectively.
I mention this because the standard Christian belief is that angels are a different class of being.
By the word “angels” (that is, “messengers” of God), we ordinarily understand a race of spiritual beings of a nature exalted far above that of man, although infinitely removed from that of God — whose office is “to do him service in heaven, and by his appointment to succor and defend men on earth”…
Angels are termed “spirits,” as in Heb. 1:14 — but it is not asserted that the angelic nature is incorporeal. The contrary seems expressly implied in Luke 20:36. The angels are revealed to us as beings such as man might be, and will be when the power of sin and death is removed, because always beholding his face, Matt. 18:10, and therefore being “made like him.” 1 John 3:2. Their number must be very large, 1 Kings 22:19; Matt. 26:53; Heb. 12:22, their strength is great, Ps. 103:20; Rev. 5:2; Rev. 18:21, their activity marvelous, Isa. 6:2-6; Matt. 26:53; Rev. 8:13, their appearance varied according to circumstances, but was often brilliant and dazzling. Matt. 28:2-7; Rev. 10:1-2. (“Angels”, Smith’s Bible Dictionary)