Elder Richard G. Scott of the Quorum of the Twelve Apostles testified that peace of conscience comes from sincere repentance and righteous living:
“God wants each of His children to enjoy the transcendent blessing of peace of conscience [see Mosiah 4:2–3]. A tranquil conscience invites freedom from anguish, sorrow, guilt, shame, and self-condemnation. It provides a foundation for happiness. …
“… You can regain peace of conscience by repenting of personal transgressions that cause you internal turmoil. …
“Broken law from sin or transgression causes anguish of mind and heart from an offended conscience. Knowing that all of His spirit children save His Only Begotten, Jesus Christ, would unintentionally or intentionally violate His laws, our Eternal Father provided a means to correct the consequences of such acts. Whether the violation be great or small, the solution is the same: full repentance through faith in Jesus Christ and His Atonement with obedience to His commandments” (in Conference Report, Oct. 2004, 14–15; or Ensign, Nov. 2004, 15–16).
President Boyd K. Packer admonished those who seek peace of conscience through repentance to persevere until they obtain forgiveness:
“The gospel teaches us that relief from torment and guilt can be earned through repentance. Save for those few who defect to perdition after having known a fulness, there is no habit, no addiction, no rebellion, no transgression, no offense exempted from the promise of complete forgiveness. …
“That great morning of forgiveness may not come at once. Do not give up if at first you fail. Often the most difficult part of repentance is to forgive yourself. Discouragement is part of that test. Do not give up. That brilliant morning will come.
“Then ‘the peace of God, which passeth … understanding’ comes into your life once again. [Philippians 4:7]. Then you, like Him, will remember your sins no more. How will you know? You will know! [see Mosiah 4:1–3]” (in Conference Report, Oct. 1995, 22, 24; or Ensign, Nov. 1995, 19–20).