Sin; the root of all evil; the spirit of the devil; possession
"Therefore to him that knoweth to do good, and doeth it not, to him it is sin" (James 4:17).
"All unrighteousness is sin" (1 John 5:17).
"Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law" (1 John 3:4).
Romans 14:23 states that "whatsoever is not of faith is sin."
"For whoso cometh not unto me is under the bondage of sin" (D&C 84:51).
Hugh Nibley points out that regarding the verb "to sin," "the Hebrew word khata properly means "to fail or miss, not to hit the mark," exactly like the Greek hamartanein (Genesis 20:6)" (Approaching Zion, 569).
Brigham Young said, "I wish you to understand that sin is not an attribute in the nature of man, but it is an inversion of the attributes God has placed in him. Righteousness tends to an eternal duration of organized intelligence, while sin bringeth to pass their dissolution" (JD 10:251).
"If we say that we have no sin, we deceive ourselves, and the truth is not in us" (1 John 1:8).
"For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all" (James 2:10).
"Do not suppose, because it has been spoken concerning restoration, that ye shall be restored from sin to happiness. Behold, I say unto you, wickedness never was happiness" (Alma 41:10).
Someone once said, "You can never get enough of what you don't need, because what you don't need won't satisfy you" (quoted by Elder Dallin H. Oaks in “Joy and Mercy,” Ensign, November 1991, 73). "Wherefore, do not spend money for that which is of no worth, nor your labor for that which cannot satisfy" (2 Nephi 9:51).
Joseph F. Smith stated, "It has been very wisely said that 'the knowledge of sin tempteth to its commission.'" (Gospel Doctrine, 373).
"The thought of foolishness is sin: and the scorner is an abomination to men" (Proverbs 24:9).
"But, behold, the judgments of God will overtake the wicked; and it is by the wicked that the wicked are punished; for it is the wicked that stir up the hearts of the children of men unto bloodshed" (Mormon 4:5).
"But behold, your days of probation are past; ye have procrastinated the day of your salvation until it is everlastingly too late, and your destruction is made sure; yea, for ye have sought all the days of your lives for that which ye could not obtain; and ye have sought for happiness in doing iniquity, which thing is contrary to the nature of that righteousness which is in our great and Eternal Head" (Helaman 13:38).
"The devil has no power over us only as we permit him" (TPJS, 181).
The root of all evil
"For the love of money is the root of all evil" (1 Timothy 6:10). "Ye cannot serve God and mammon" (Matthew 6:24).
We may try to brush off the former scripture easily, thinking "oh, I'm no lover of money." But if that's true, then why do we continue to do evil, to sin?
If the love of money's the root of all evil, what about during the Council in Heaven? Assuming there wasn't "money" there, how could it be the root of the evil that caused the dissension there? "Love of money" was translated from the greek word philarguria, "which simply means desire for wealth" (Hugh Nibley, Approaching Zion, 142).
Someone named Pastor Ahyh wrote, "Money represents the potential to manifest the material world according to one's wishes. Money = physical options. Why does anyone want money? Because of its abilities to provide what we think we want. The quest for money is the quest for the material world. Desire for money is an expression of attachment to the material world. And why do we seek to manifest the material world? Because we think it will provide comfort, happiness, satisfaction, peace, etc."
The spirit of the devil
Errol R. Fish hypothesized, "Satan may well have spirit in the universe that obeys him, called: the Spirit of the Devil, Satan's Spirit, the Evil Spirit, or Lucifer's Spirit. All spirit is independent in that sphere where God has placed it, to act for itself; and there may be spirit that chooses, of its own free will, to serve Satan" (Promptings of the Spirit, 209).
John Taylor said, "There have been from the foundation of the world two principles and powers--the principles of darkness and the principles of light, the principles of truth and the principles of error, the Spirit of God and the spirit of the Devil;--and there has been a mighty struggle between these two principles and powers. Hitherto the good, the virtuous, the pure and upright, the men of God, the Saints of the Most High have been trampled under foot and cast out--have wandered about in sheep-skins and goat-skins, dwelt in deserts, dens, holes, and caves of the earth, of whom the world was not worthy; and the spirit and power of darkness have prevailed over the powers of light, error over truth, and the spirit of the Wicked One over the Spirit of God, to a certain extent; so much so, that truth, equity, and righteousness have always been at a discount, and men of God have been deprived of their rights and robbed of their inheritances. God has had a certain design to accomplish, associated with the human family; and I suppose that everything which has taken place has been just. I am not going to find fault with God or the Devil. I suppose the Devil is as necessary as any other being, or he would not have been" (JD 6:22-3).
President Joseph F. Smith wrote that the Spirit of God "is the power or the spirit that 'lighteneth every man that cometh into the world,' that prompteth a man to do good, speak the truth, love his neighbor as himself and to 'serve God and keep all His commandments.' This Spirit of the Lord is the antithesis of the spirit of the Devil" (James R. Clark, Messages of the First Presidency 4:33).
In the Dead Sea Scrolls it is written, "All that is now and ever shall be originates with the God of knowledge. Before things come to be, He has ordered all their designs, so that when they do come to exist-- at their appointed times as ordained by His glorious plan-- they fulfill their destiny. . . . He created humankind to rule over the world, appointing for them two spirits in which to walk until the time ordained for His visitation. These are the spirits of truth and falsehood. Upright character and fate originate with the Habitation of Light; perverse, with the Fountain of Darkness. The authority of the Prince of Light extends to the governance of all righteous people; therefore, they walk in the paths of light. Correspondingly, the authority of the Angel of Darkness embraces the governance of all wicked people, so they walk in the paths of darkness. The authority of the Angel of Darkness further extends to the corruption of all the righteous. All their sins, iniquities, shameful and rebellious deeds are at his prompting, a situation God in His mysteries allows to continue until His era dawns. Moreover, all the afflictions of the righteous, and every trial in its season, occur because of this Angel's diabolic rule. All the spirits allied with him share but a single resolve: to cause the Sons of Light to stumble" (Wise et al., The Dead Sea Scrolls, 120-1).
Charles W. Penrose thought that "there must be, as the Book of Mormon says, 'an opposition in all things,' and there is a spirit of evil, a spirit of darkness, which draws downward to death, and a spirit of light which leads upward to life; the one leads to Satan and his works, the other to God and to righteousness. But the inhabitants of the earth generally have been more prone to listen to the inspiration of the spirit of darkness as did our first parents, than to listen to the still small voice of light and life in their souls" (JD 21:82-3).
"And now, my sons, I would that ye should look to the great Mediator, and hearken unto his great commandments; and be faithful unto his words, and choose eternal life, according to the will of his Holy Spirit; And not choose eternal death, according to the will of the flesh and the evil which is therein, which giveth the spirit of the devil power to captivate, to bring you down to hell, that he may reign over you in his own kingdom" (2 Nephi 2:28-9).
"And it speaketh harshly against sin, according to the plainness of the truth; wherefore, no man will be angry at the words which I have written save he shall be of the spirit of the devil" (2 Nephi 33:5).
"I saw armies arrayed against armies. I saw blood, desolation, fires. The Son of man has said that the mother shall be against the daughters, and the daughter against the mother. These things are at our doors. They will follow the Saints of God from city to city. Satan will rage, and the spirit of the devil is now enraged" (TPJS, 161). "There are three independent principles; the Spirit of God, the spirit of man, and the spirit of the devil. All men have power to resist the devil" (TPJS, 189). Joseph Smith asked, "who can drag into daylight and develop the hidden mysteries of the false spirits that so frequently are made manifest among the Latter-day Saints? We answer that no man can do this without the Priesthood, and having a knowledge of the laws by which spirits are governed; for as no man knows the things of God, but by the Spirit of God, so no man knows the spirit of the devil, and his power and influence, but by possessing intelligence which is more than human" (TPJS, 204). "When a man begins to be an enemy to this work, he hunts me, he seeks to kill me, and never ceases to thirst for my blood. He gets the spirit of the devil—the same spirit that they had who crucified the Lord of Life—the same spirit that sins against the Holy Ghost. You cannot save such persons; you cannot bring them to repentance; they make open war, like the devil, and awful is the consequence" (TPJS, 358).
Brigham Young said, "Do you not know that Jesus told the truth when he said, 'They what are not for us are against us?' A great many have our patronage and influence, benefit by our forbearance, and enrich themselves with our cash, but when that is gone, what shall we hear next? 'Wipe them from the earth, put them out of existence and let the earth not be infested with them any longer, for they have no money, no influence for us now; they cannot patronize and promote us, therefore destroy them from the earth.' That is the spirit of the devil which reigns in every man who is not a saint at heart. This wicked principle may lay dormant, to all appearance, year after year, lurking in the flesh, until it increases to such a degree that the flesh has overcome the spirit of light which God implanted in them, when it exhibits itself, and then the cry is, "Destroy the Apostles of Jesus and every one of his true followers; root out that clan which will destroy us unless we destroy them; root them out, that we be no more pestered with them" (JD 3:225).
The above scriptures and quotes indicate that multiple people can have the spirit of the devil. But just like the Holy Ghost, the devil can only be in one place at one time. It is the spirit of God that can be in many righteous people at once. In the subsection"The Infinite Holarchy of Spirit", it had been noted that spirit matter is involved in higher and lower levels. So actually, any spirit that would entice someone to a lower level would be of the devil in a sense, because it would be stopping our upward progress.
It may be possible that idle speculation, seeking too far above our current level, may be detrimental. D&C 93:24-5 states that "truth is knowledge of things as they are, and as they were, and as they are to come; And whatsoever is more or less than this [truth] is the spirit of that wicked one who was a liar from the beginning." So we may be enticed to seek more than what is necessary for us at the level we comprehend, or have knowledge of. Jacob 4:14 states that "the Jews were a stiffnecked people; and they despised the words of plainness, and killed the prophets, and sought for things that they could not understand. Wherefore, because of their blindness, which blindness came by looking beyond the mark, they must needs fall; for God hath taken away his plainness from them, and delivered unto them many things which they cannot understand, because they desired it. And because they desired it God hath done it, that they may stumble."
Possession
"Ye cannot say, when ye are brought to that awful crisis, that I will repent, that I will return to my God. Nay, ye cannot say this; for that same spirit which doth possess your bodies at the time that ye go out of this life, that same spirit will have power to possess your body in that eternal world. For behold, if ye have procrastinated the day of your repentance even until death, behold, ye have become subjected to the spirit of the devil, and he doth seal you his; therefore, the Spirit of the Lord hath withdrawn from you, and hath no place in you, and the devil hath all power over you; and this is the final state of the wicked. And this I know, because the Lord hath said he dwelleth not in unholy temples, but in the hearts of the righteous doth he dwell" (Alma 34:34-6).
"And then shall it come to pass, that the spirits of the wicked, yea, who are evil--for behold, they have no part nor portion of the Spirit of the Lord; for behold, they chose evil works rather than good; therefore the spirit of the devil did enter into them, and take possession of their house--and these shall be cast out into outer darkness; there shall be weeping, and wailing, and gnashing of teeth, and this because of their own iniquity, being led captive by the will of the devil. Now this is the state of the souls of the wicked, yea, in darkness, and a state of awful, fearful looking for the fiery indignation of the wrath of God upon them; thus they remain in this state, as well as the righteous in paradise, until the time of their resurrection" (Alma 40:13-4).
"Imagining up some vain thing in their hearts, that it was wrought by men and by the power of the devil, to lead away and deceive the hearts of the people; and thus did Satan get possession of the hearts of the people again, insomuch that he did blind their eyes and lead them away to believe that the doctrine of Christ was a foolish and a vain thing. And it came to pass that the people began to wax strong in wickedness and abominations; and they did not believe that there should be any more signs or wonders given; and Satan did go about, leading away the hearts of the people, tempting them and causing them that they should do great wickedness in the land" (3 Nephi 2:2-3).
"For this is the will of God, even your sanctification, that ye should abstain from fornication: That every one of you should know how to possess his vessel in sanctification and honour; Not in the lust of concupiscence" (1 Thessalonians 4:3-5).
"In your patience possess ye your souls" (Luke 21:19). "And seek the face of the Lord always, that in patience ye may possess your souls, and ye shall have eternal life" (D&C 101:38).