For this is, second, the fruit of true, sincere repentance, that by it we obtain forgiveness of sins and peace of conscience. This is why it is called “repentance unto life” (Acts 11:18), and “repentance and the forgiveness of sins” are placed together as pointing to one another (Luke 24:47, Acts 2:38). For true faith in Christ is also a part, and, to be sure, the chief part, of repentance, by which we are justified before God and our conscience is placed at ease. Romans 5:1, “Now that we have been justified by faith, we have peace with God through our Lord Jesus Christ.”
When the heart, distressed by sin, grasps with true faith the promise of the forgiveness of sins that has been won for us by Christ, then peace and tranquility of conscience follow. Then a person tastes how friendly the Lord is (Psa. 34:9). Yes, a beginning of eternal life is made, since this is nothing other than the fullness of joy in God.
(Sermon for Mary Magdalene-July 22, Postilla Volume 3 by Johann Gerhard, Repristination Press, page 113)