Man is not justified by the law of Moses. He is justified through righteousness, which comes through faith in Christ, made possible through Christ’s atoning sacrifice.
Romans 3:23
23 For all have sinned, and come short of the glory of God . . .
President Ezra Taft Benson said:
“Why must faith in the Lord precede true repentance?
“To answer this question, we must understand something about the atoning sacrifice of the Master. Lehi taught that ‘no flesh . . . can dwell in the presence of God, save it be through the merits, and mercy, and grace of the Holy Messiah.’ (2 Ne. 2:8.) Even the most just and upright man cannot save himself solely on his own merits, for, as the Apostle Paul tells us, ‘all have sinned, and come short of the glory of God.’ (Rom. 3:23.)
“If it were not for the perfect, sinless life of the Savior, which He willingly laid down for us, there could be no remission of sins.
“Therefore, repentance means more than simply a reformation of behavior. Many men and women in the world demonstrate great willpower and self-discipline in overcoming bad habits and the weaknesses of the flesh. Yet at the same time they give no thought to the Master, sometimes even openly rejecting Him. Such changes of behavior, even if in a positive direction, do not constitute true repentance.
“Faith in the Lord Jesus Christ is the foundation upon which sincere and meaningful repentance must be built. If we truly seek to put away sin, we must first look to Him who is the Author of our salvation.”
(Teachings of Presidents of the Church: Ezra Taft Benson [2014], 79.)