"For behold that all little children are alive in Christ, and also all they that are without the law. For the power of redemption cometh on all them that have no law; wherefore, he that is not condemned, or he that is under no condemnation, cannot repent; and unto such baptism availeth nothing--" - Moroni 8:22

law
1    /lɔ/ Show Spelled[law] Show IPA noun
1. the principles and regulations established in a community by some authority and applicable to its people, whether in the form of legislation or of custom and policies recognized and enforced by judicial decision. - dictionary.com

A3. Sin is defined as knowingly acting against the will of God.

"And now, how much more cursed is he that knoweth the will of God and doeth it not, than he that only believeth, or only hath cause to believe, and falleth into transgression?" - Alma 32:19

If we assume the other group is exempt for the same reason as children, it would be those who never achieve the mental capacity to make decisions. They are therefore not accountable for their actions.

The knowledge required to sin is not just belief or cause to believe, as we have when someone tells us from the pulpit or we read it in the scriptures or hear the prophet tell us, it means real personal "knowledge".

For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise.

Wherefore then serveth the law? It was added because of transgressions, till the seed should come to whom the promise was made; and it was ordained by angels in the hand of a mediator." - Gal. 3:18-19

Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.

And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise." - Gal. 3:16-18

Is the law then against the promises of God? God forbid: for if there had been a law given which could have given life, verily righteousness should have been by the law.

Christ hath redeemed us from the bcurse of the law" - Gal. 3:13

"Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.

But after that faith is come, we are no longer under a schoolmaster." - Gal. 3:24-25

Love worketh no ill to his neighbour: therefore love is the fulfilling of the law. - Romans 13:10

For sin shall not have dominion over you: for ye are not under the law, but under grace.

What then? shall we sin, because we are not under the law, but under grace? bGod forbid. - Romans 6:14-15 (See also 14-18

For we know that the commandment is spiritual; but when I was under the law, I was yet carnal, sold under sin. - JST Romans 7:14

But if ye be led of the Spirit, ye are not under the law. - Gal. 5:18

Your original quote was from the Book of Mormon. Can you provide evidence as to which law Mormon was referring to in his epistle?

"For behold that all little children are alive in Christ, and also all they that are without the law. For the power of redemption cometh on all them that have no law; wherefore, he that is not condemned, or he that is under no condemnation, cannot repent; and unto such baptism availeth nothing--" - Moroni 8:22

Now we know that the Law of Moses was fulfilled by Christ, as He was the one who gave the law to begin with. Why did He give it?

Now this Moses plainly taught to the children of Israel in the wilderness, and sought diligently to sanctify his people that they might behold the face of God;

But they hardened their hearts and could not endure his presence; therefore, the Lord in his wrath, for his anger was kindled against them, swore that they should not enter into his rest while in the wilderness, which rest is the fulness of his glory.

Therefore, he took Moses out of their midst, and the Holy Priesthood also;

And the lesser priesthood continued, which priesthood holdeth the key of the ministering of angels and the preparatory gospel;

Which gospel is the gospel of repentance and of baptism, and the remission of sins, and the law of carnal commandments, which the Lord in his wrath caused to continue with the house of Aaron among the children of Israel until John, whom God raised up, being filled with the Holy Ghost from his mother's womb.

• The reason for giving the Law of Moses was, as you said, because the people would not enter into the presence of God.
  
• The church members today have, for the most part, still not entered into God's presence.
  
• We live the same law discribed in D&C 84 that was attributed to those who are cursed for not entering into God's presence.
  
• This is a PREPARATORY law (& Gospel) given to prepare people to enter into God's presence.
  
• This preparatory law and gospel includes faith, repentance, baptism, and the law of Carnal commandments.
  
• The system is easy, break the carnal commandments and you need to repent. Breaking these commandments is a sin.
  
• The surprising conclusion is, No Lower/preparatory law = No Law of Carnal Commandments to break = no sin to repent from, no need to be saved from the punishment of a broken law.
  

Now, how could a man repent except he should sin? How could he sin if there was no law? How could there be a law save there was a punishment? - Alma 42:17

Therefore leaving the principles of the doctrine of Christ, let us go on unto perfection; not laying again the foundation of repentance from dead works, and of faith toward God,

Of the doctrine of baptisms, and of laying on of hands, and of resurrection of the dead, and of eternal judgment.

And this will we do, if God permit.

For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost,

And have tasted the good word of God, and the powers of the world to come,

If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God fresh, and put him to an open shame. - Heb. 6:1-6

Now, if there was no law given--if a man murdered he should die--would he be afraid he would die if he should murder?

And also, if there was no law given against sin men would not be afraid to sin. - Alma 42:19-20

In the end, there is a "Final Repentance" after which no further repentance is required nor will it do you any good. At this point, the law has been fulfilled and you are no longer under the law.

But even God repents and corrects any bad actions as God grows and learns. Isn't that repentance?

For behold, if a man being evil giveth a gift, he doeth it grudgingly; wherefore it is counted unto him the same as if he had retained the gift; wherefore he is counted evil before God.

And likewise also is it counted evil unto a man, if he shall pray and not with real intent of heart; yea, and it profiteth him nothing, for God receiveth none such.

Wherefore, a man being evil cannot do that which is good; neither will he give a good gift.

Just because I have my C&E doesn't mean I don't accidentally hurt others or fail to be the best person I am striving to be.

How does that mean I don't need a law or to repent??

This is the covenant that I will make with them after those days, saith the Lord, I will put my laws into their hearts, and in their minds will I write them;

And their sins and iniquities will I remember no more.

Now where remission of these is, there is no more offering for sin. - Heb 10:16-18

Hearken unto me, ye that know righteousness, the people in whose heart I have written my law, fear ye not the reproach of men, neither be ye afraid of their revilings. - 2 Nephi 8:7

Master, which is the great commandment in the law?

Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind.

This is the first and great commandment.

And the second is like unto it, Thou shalt love thy neighbour as thyself.

On these two commandments hang all the law and the prophets. - Matt. 22:36-40

Does God repent? Yes, if we can agree to define repentance as progression. God is constantly progressing as he helps us and all creation to progress. However I am not in a position to know whether he repents of transgressions. I think we can all agree that he is without sin.

Now, how could a man repent except he should sin? How could he sin if there was no law? How could there be a law save there was a punishment? - Alma 42:17

"And God saw their works, that they turned from their evil way; and God repented of the evil, that he had said that he would do unto them; and he did it not.- Jonah 3:10"

1. Children who have not been given the law
   
2. Anyone who has not been given the law
   
3. Anyone who has mastered the principles behind the law thus fulfilling the law