But behold, ye have rejected the truth, and rebelled against your holy God; and even at this time, instead of laying up for yourselves treasures in heaven, where nothing doth corrupt, and where nothing can come which is unclean, ye are heaping up for yourselves wrath against the day of judgment. (Helaman 8:25)
Sin is when we act contrary to our understanding of God’s will. If we knowingly sin, we are in open rebellion against God; we are cut off from God and will be forever until we repent.
But behold, and fear, and tremble before God, for ye ought to tremble; for the Lord redeemeth none such that rebel against him and die in their sins; yea, even all those that have perished in their sins ever since the world began, that have wilfully rebelled against God, that have known the commandments of God, and would not keep them; these are they that have no part in the first resurrection. (Mosiah 15:26)
Some seek to excuse themselves in willful disobedience by claiming that the blood of Jesus will save them in spite of their sin. Jesus cannot save his people in their sins. He can only save them from their sins.
And, in fine, wo unto all those who die in their sins; for they shall return to God, and behold his face, and remain in their sins. (2 Nephi 9:38)
His sacrifice absolves the repentant from the penalty of their past sins. To absolve a man for his willful disobedience while he still persists in sin would be to deny the justice of God.
Personal repentance is required for one to be cleaned by the blood of Jesus:
And I say unto you again that he cannot save them in their sins; for I cannot deny his word, and he hath said that no unclean thing can inherit the kingdom of heaven; therefore, how can ye be saved, except ye inherit the kingdom of heaven? Therefore, ye cannot be saved in your sins. (Alma 11:3)
Clearly, Jesus requires us to fully submit to him and his instructions to us. A partial sacrifice is not an acceptable one. The Lord does not forgive a sin. You won't find a single instance of his forgiving a sin in the entire cannon. When he forgives you of your sins, he forgives you of all of them all at once. You can’t repent of just one sin. You have to repent of all of your sins. “Therefore they did forsake all their sins, and their abominations, and their whoredoms, and did serve God with all diligence day and night.” (3 Nephi 5:3)
Repentance is not just about forgiveness of sins. It is incomplete unless and until you have changed your attitude. True repentance occurs only when you completely subject yourself to God’s will in your life. There are no partial sacrifices.
Too many people today believe that they can persist in disobeying God and still be saved. Their inheritance is hell:
But behold, and fear, and tremble before God, for ye ought to tremble; for the Lord redeemeth none such that rebel against him and die in their sins; yea, even all those that have perished in their sins ever since the world began, that have wilfully rebelled against God, that have known the commandments of God, and would not keep them; these are they that have no part in the first resurrection. (Mosiah 15:26)
These must believe that somehow they will be able to lie to God on the judgment day, and stand up to his all-piercing eye, knowing full well that they rejected him and their chance at salvation:
15 Do you look forward with an eye of faith, and view this mortal body raised in immortality, and this corruption raised in incorruption, to stand before God to be judged according to the deeds which have been done in the mortal body?
16 I say unto you, can you imagine to yourselves that ye hear the voice of the Lord, saying unto you, in that day: Come unto me ye blessed, for behold, your works have been the works of righteousness upon the face of the earth?
17 Or do ye imagine to yourselves that ye can lie unto the Lord in that day, and say—Lord, our works have been righteous works upon the face of the earth—and that he will save you?
18 Or otherwise, can ye imagine yourselves brought before the tribunal of God with your souls filled with guilt and remorse, having a remembrance of all your guilt, yea, a perfect remembrance of all your wickedness, yea, a remembrance that ye have set at defiance the commandments of God?
19 I say unto you, can ye look up to God at that day with a pure heart and clean hands? I say unto you, can you look up, having the image of God engraven upon your countenances?
20 I say unto you, can ye think of being saved when you have yielded yourselves to become subjects to the devil?
21 I say unto you, ye will know at that day that ye cannot be saved; for there can no man be saved except his garments are washed white; yea, his garments must be purified until they are cleansed from all stain, through the blood of him of whom it has been spoken by our fathers, who should come to redeem his people from their sins.
22 And now I ask of you, my brethren, how will any of you feel, if ye shall stand before the bar of God, having your garments stained with blood and all manner of filthiness? Behold, what will these things testify against you?
23 Behold will they not testify that ye are murderers, yea, and also that ye are guilty of all manner of wickedness?
24 Behold, my brethren, do ye suppose that such an one can have a place to sit down in the kingdom of God, with Abraham, with Isaac, and with Jacob, and also all the holy prophets, whose garments are cleansed and are spotless, pure and white?
25 I say unto you, Nay; except ye make our Creator a liar from the beginning, or suppose that he is a liar from the beginning, ye cannot suppose that such can have place in the kingdom of heaven; but they shall be cast out for they are the children of the kingdom of the devil. (Alma 5)
Heaven’s gates are closed tightly against all who willingly sin against God.
But wo, wo unto him who knoweth that he rebelleth against God! For salvation cometh to none such except it be through repentance and faith on the Lord Jesus Christ. (Mosiah 3:12)
But remember that he that persists in his own carnal nature, and goes on in the ways of sin and rebellion against God, remaineth in his fallen state and the devil hath all power over him. Therefore he is as though there was no redemption made, being an enemy to God; and also is the devil an enemy to God. (Mosiah 16:5)
Their experience in the day of judgment will be far different from their expectations:
1 And now, it came to pass that after Abinadi had spoken these words he stretched forth his hand and said: The time shall come when all shall see the salvation of the Lord; when every nation, kindred, tongue, and people shall see eye to eye and shall confess before God that his judgments are just.
2 And then shall the wicked be cast out, and they shall have cause to howl, and weep, and wail, and gnash their teeth; and this because they would not hearken unto the voice of the Lord; therefore the Lord redeemeth them not.
3 For they are carnal and devilish, and the devil has power over them; yea, even that old serpent that did beguile our first parents, which was the cause of their fall; which was the cause of all mankind becoming carnal, sensual, devilish, knowing evil from good, subjecting themselves to the devil.
4 Thus all mankind were lost; and behold, they would have been endlessly lost were it not that God redeemed his people from their lost and fallen state.
5 But remember that he that persists in his own carnal nature, and goes on in the ways of sin and rebellion against God, remaineth in his fallen state and the devil hath all power over him. Therefore he is as though there was no redemption made, being an enemy to God; and also is the devil an enemy to God. (Mosiah 16:1-5)
Those who willingly disobey God are not only not saved, they also cut themselves off from the influence of the Spirit of God:
36 And now, I say unto you, my brethren, that after ye have known and have been taught all these things, if ye should transgress and go contrary to that which has been spoken, that ye do withdraw yourselves from the Spirit of the Lord, that it may have no place in you to guide you in wisdom’s paths that ye may be blessed, prospered, and preserved—
37 I say unto you, that the man that doeth this, the same cometh out in open rebellion against God; therefore he listeth to obey the evil spirit, and becometh an enemy to all righteousness; therefore, the Lord has no place in him, for he dwelleth not in unholy temples.
38 Therefore if that man repenteth not, and remaineth and dieth an enemy to God, the demands of divine justice do awaken his immortal soul to a lively sense of his own guilt, which doth cause him to shrink from the presence of the Lord, and doth fill his breast with guilt, and pain, and anguish, which is like an unquenchable fire, whose flame ascendeth up forever and ever.
39 And now I say unto you, that mercy hath no claim on that man; therefore his final doom is to endure a never-ending torment.
40 O, all ye old men, and also ye young men, and you little children who can understand my words, for I have spoken plainly unto you that ye might understand, I pray that ye should awake to a remembrance of the awful situation of those that have fallen into transgression. (Mosiah 2)
It is impossible for one in willful disobedience to come to know God. It is impossible for them to do the mighty works that are the privilege of all believers in Christ.