Too many believe that sinlessness isn’t possible. They incorrectly project their own unbelief and lack of conviction onto others. Their choice not to do something doesn’t make it impossible for those who do. Jesus, our example in all things, lived a sinless life:
For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin. (Hebrews 4:15)
Though he was born as the Son of God, he was also “in all points tempted like as we are,” but he never sinned, showing that there is nothing about our mortal bodies that precludes us from living without sin.
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.
7 Know ye not that he was holy? But notwithstanding he being holy, he showeth unto the children of men that, according to the flesh he humbleth himself before the Father, and witnesseth unto the Father that he would be obedient unto him in keeping his commandments.
8 Wherefore, after he was baptized with water the Holy Ghost descended upon him in the form of a dove.
9 And again, it showeth unto the children of men the straitness of the path, and the narrowness of the gate, by which they should enter, he having set the example before them.
10 And he said unto the children of men: Follow thou me. Wherefore, my beloved brethren, can we follow Jesus save we shall be willing to keep the commandments of the Father? (2 Nephi 31)
Though Jesus was the only human who kept all of the commandments of which he was aware from birth, many others have followed his example after learning of him.
Many have shown us that sinlessness is possible. Through their example, you are left without excuse.
The highest courts of heaven are filled with “an innumerable number” of those who stopped sinning in life:
22 But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels,
23 To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect, (Hebrews 12)
We know the names of at least some of these people. Noah, for instance, “was a just man and perfect in his generations, and [he]walked with God.” (Genesis 6:9) The Israelite king “Asa’s heart was perfect with the Lord all his days.” (1 Kings 15:14) The prophet Nephi “kept the commandments from the time” he learned about the Lord (see 2 Nephi 1:24, see also 1 Nephi 5:20). Job “was perfect and upright, and one that feared God, and eschewed evil.” (Job 1:1) Many more men attained to a sinless life, including Adam, Enoch, Abel, Seth, Abraham, Moses, Elijah, and John.
Some may be tempted to disregard these examples with some excuse like, “yes, but these are special people. I’m not special, so it’s too hard for me to be sinless.”
Obedience isn’t easier for some people than others. All people have the same capacity for obedience to God. “He fashioneth [all mens’] hearts alike; he considereth all their works.” (Psalm 33:15)
Even the most righteous people have to overcome the same struggles we all face. “Elias was a man subject to like passions as we are...” (James 5:17) The Lord Jesus himself was “...in all points tempted like as we are, yet without sin.” (Hebrews 4:15) Jesus faced and overcame all potential obstacles in life, demonstrating it can be done. 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)
God has given you the power not to sin. You can obey everything God tells you, and you must if you desire to be saved and live with him in heaven.