Such is the confidence that we have through Christ toward God. Not that we are competent of ourselves to claim anything as coming from us; our competence is from God, who has made us competent to be ministers of a new covenant, not in a written code but in the Spirit; for the written code kills, but the Spirit gives life. 2 Corinthians 3:4–6 (RSV)
Luther entered the monastery in the hope of finding peace with God. God is holy beyond any human ability to receive. Jesus was the righteous judge who will hold the sinner to account for their every transgression.
Luther understood human frailty all too well. He saw his sin with a clarity that terrified him. As a monk, he kept all the rules, fasts, vigils, and disciplines demanded by his order. He found no lasting peace in all these things. He hoped that confessing his sins would give him relief. He would confess his sins for hours, only to discover more sin as he left the confessional. An exasperated confessor once declared, "Murder your father, so you have some real sin to confess!"
The way of the Law and human effort gave no release. The Law demands 'do this,' and it is never done. This Luther knew all too well.
His assignment to teach and preach on the Scriptures that the Spirit opened his heart to God's grace and mercy. The Word revealed to him the God whose love for the world was shown in the dying and rising of His Son. Once Luther saw that it is by faith in what Christ has done that we are saved, he was free from the terror of God.
St. Paul and Luther witness to us that we have no confidence in our righteousness. Our confidence is in Jesus alone, who has fulfilled the Law. Joined to His dying and rising through our baptism into His death, we now are confident of salvation.