Is it possible to keep all of God’s commandments? If you don’t think so, chances are you have adopted a theology where God permits at least some sin. Man’s failure, not God’s word, is the source of that false doctrine.
Only those who believe it is possible will ever try. In order to become sinless, it requires faith in God. It is impossible to exercise God’s power without faith, and it is impossible to have faith in a principle that you do not believe could be true. In order to describe how to become sinless, we must first show that it is possible.
That the goal of the gospel is to produce sinless men is undeniable. Paul described his mission as perfecting every man in Christ Jesus:
Whom we preach, warning every man, and teaching every man in all wisdom; that we may present every man perfect in Christ Jesus: (Colossians 1:28)
In another letter, he clarified that “perfect in Christ” meant to achieve a stature similar to that of Jesus:
Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ: (Ephesians 4:13)
Mormon described the possibility of being found spotless at the great and last day:
O then ye unbelieving, turn ye unto the Lord; cry mightily unto the Father in the name of Jesus, that perhaps ye may be found spotless , pure, fair, and white, having been cleansed by the blood of the Lamb, at that great and last day. (Mormon 9:6)
John the Revelator described true disciples of God as those who purify themselves, becoming like Jesus by not sinning and keeping Jesus’ commandments:
1 Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not.
2 Beloved, now are we the sons of God, and it doth not yet 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.
3 And every man that hath this hope in him purifieth himself, even as he is pure.
4 Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.
5 And ye know that he was manifested to take away our sins; and in him is no sin.
6 Whosoever abideth in him sinneth not: whosoever sinneth hath not seen him, neither known him.
7 Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.
8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
9 Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God.
10 In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother. (1 John 3)
Jesus, our example in all things, lived a sinless life. One of the reasons Jesus had to come to this earth as a man is to prove that it is within the capacity of man to perfectly obey God. If it were not so, God could not justly require full obedience to him.
It is possible to become free from sin:
...that ye may become the sons of God; that when he shall appear we shall be like him, for we shall see him as he is; that we may have this hope; that we may be purified even as he is pure. Amen. (Moroni 7:48)
It is also essential.