D&C 130: 20 There is a law, irrevocably decreed in heaven before the foundations of this world, upon which all blessings are predicated—
21 And when we obtain any blessing from God, it is by obedience to that law upon which it is predicated.
as well as
D&C 132:5 For all who will have a blessing at my hands shall abide the law which was appointed for that blessing, and the conditions thereof, as were instituted from before the foundation of the world.
The atonement of Christ does absolutely nothing to alter the truth of either of these scriptures. In fact, both scriptures were given as words of revelation from God himself and both were given after the atonement had already been performed. They are not oversights nor did God forget about the
atonement when he revealed them.
These two verses, properly understood, throw enough light on the doctrine of the atonement to wipe away much of the veil of darkness Satan has held over the eyes of the world.
There is no sense in which the grace of Christ allows us to "skip to the end" from the point at which we die to the point we are at when we die to the point where we are so perfect that we can live with a God who cannot look upon sin with the least degree of allowance.
The grace of Christ provides no such benefit. We will not enter the celestial kingdom a single day before we have changed to the point where not only do we no longer sin, but where we can, with our Father, say that we cannot look upon sin with the least degree of allowance.
The grace of Christ does not, in any way, change the fact that in order to get into heaven we need to change. The atonement does absolutely nothing to change how much we need to change.
These scriptures directly contradict many commonly preached ideas about the atonement. That is because those ideas are not what the atonement is about at all. They are complete fabrications.
Joseph Smith taught:
In order to have this subject clearly set before the mind, let us ask what situation must a person be in, in order to be saved? or what is the difference between a saved man and one who is not saved? We answer from what we have before seen of the heavenly worlds, they must be persons who can work by faith, and who are able, by faith to be ministering spirits to them who shall be heirs of salvation. And they must have faith to enable them to act in the presence of the Lord, otherwise they cannot be saved. And what constitutes the real difference between a saved person and one not saved, is the difference in the degree of their faith: one's faith has become perfect enough to lay hold upon eternal life, and the other's has not. But to be a little more particular, let us ask, where shall we find a prototype into whose likeness we may be assimulated, in order that we may be made partakers of life and salvation? or in other words, where shall we find a saved being? for if we can find a saved being, we may ascertain, without much difficulty, what all others must be, in order to be saved - they must be like that individual or they cannot be saved: we think, that it will not be a matter of dispute, that two beings, who are unlike each other, cannot both be saved; for whatever constitutes the salvation of one, will constitute the salvation of every creature which will be saved: and if we find one saved being in all existence, we may see what all others must be, or else not be saved. We ask, then, where is the prototype? or where is the saved being? We conclude as to the answer of this question there will be no dispute among those who believe the bible, that it is Christ: all will agree in this that he is the prototype or standard of salvation, or in other words, that he is a saved being. And if we should continue our interogation, and ask how it is that he is saved, the answer would be, because he is
a just and holy being; and if he were any thing different from what he is he would not be saved; for his salvation depends on his being precisely what he is and nothing else; for if it were possible for him to change in the least degree, so sure he would fail of salvation and lose all his dominion, power, authority and glory, which constitutes salvation; for salvation consists in the glory, authority, majesty, power and dominion which Jehovah possesses, and in nothing else; and no being can possess it but himself or one like him: Thus says John, in his first epistle, 3:2 and 3: Behold, now we are the sons of God, and it doth not appear what we shall be; but we know, that when he shall appear we shall be like him; for we shall see him as he is. And any man that has this hope in him purifies himself, even as he is pure.--Why purify himself as he is pure? because, if they do not they cannot be like him.
The Lord said unto Moses, Leviticus, 19:2:--Speak unto all the congregation of the children of Israel, and say unto them, Ye shall be holy: for I the Lord your God am holy. And Peter says, first epistle, 1:15 and 16: But as he who has called you is holy, so be ye holy in all manner of conversation; because it is written, Be ye .holy; for I am holy. And the Savior says, Matthew, 15:48: Be ye perfect, even as your Father who is in heaven is perfect. If any should ask why all these sayings? the answer is to be found from what is before quoted from John's epistle, that when he (the Lord) shall appear, the saints will be like him: and if they are not holy, as he is holy, and perfect as he is perfect, they cannot be like him; for no being can enjoy his glory without possessing his perfections and holiness, no more than they could reign in his kingdom without his power. (Lectures on Faith, 7:9-10)