Martin Luther for many years early in his life was tormented in mind and soul, constantly sensing his sin before God and yet seeing only the heavy hand of a righteous God who must judge sin and execute justice.
Because Luther perceived that his own situation before God was utterly dire and its indictments inescapable, of being condemned under God’s judgment against sin, and in fact due to his biblical realization of sin, he actually hated God for many years since he knew that he stood condemned. He discovered, to his great dismay, that it was actually impossible to confess every little sin; especially when sometimes our sins are imperceptible to our undiscerning mind (the Bible refers to these as “hidden faults” Psalm 19:12).

Luther was almost driven mad by a pressing urgency to confess his sins immediately – at all times throughout the day – and in entirety to his mentor Johann von Staupitz. After he had confessed and gone away he would think of yet another sin that he had forgotten to repent of and would turn back around, retrace his steps, and go to confess again. Martin had a conscience that constantly pricked him and it seemed sometimes that he didn’t know why God wouldn’t just leave him (and his conscience) alone.
He joined a strict monastic order and subjected himself to bodily injury and deprivation, as many monks at that time did in the hope of expunging the fleshly desires from one’s self. And yet Martin at that time did not realize what the Apostle Paul meant when he said, “These are matters which have, to be sure, the appearance of wisdom in self-made religion and self-abasement and severe treatment of the body, but are of no value against fleshly indulgence” (Colossians 2:23). But he knew something was missing and kept pressing on.
Dr. Timothy George (Dean of Beeson Divinity School, Samford University) gave an excellent lecture at Dallas Theological Seminary on this topic of how Luther’s theology developed over time, which is recorded in the following video:
Dr. George speaks about the story regarding Luther’s constant repenting between 11:00-14:15 in the video. He also points out elsewhere in the lecture that Luther had a realization from Scripture, long before Carl Jung, that the human psyche has depths and layers – things that are even unconscious to us – and that all of it needs to be redeemed. Luther realized that it is not enough to just confess the sins that we are conscious of but that everything must be forgiven us else we are still in sin. As Luther learned, if redemption is based on our own confession and penitence it is impossible to attain it.
Luther eventually came to the knowledge that we are utterly sinful and cannot be made right apart from faith and the work of God by grace in us. But Luther did not see God as gracious at first, or how he could be reconciled to a just God, as Dr. George explains. It was not until Luther had his monumental breakthrough in his understanding of how we are justified in Jesus through faith alone that he saw that God’s atonement for sins is all-sufficient toward those who have true faith in Him. But in the course of his journey to discovering that truth the burden of the seriousness of sin and the biblical certainty of final judgment had sunk in with Luther.
We, I think, should all take sin just as seriously and make sure that we act in accordance with what Paul wrote to the Corinthians about our coming judgment before Christ: “Knowing therefore the terror of the Lord, we persuade men” (2 Corinthians 5:11). Hence we should “work out our salvation with fear and trembling” (Philipians 2:12). If we don’t take the responsibility of departing from sin seriously then we are not doing our duty as a Christian. As it says in the Scripture: “Let everyone who names the name of the Lord depart from iniquity” (2 Timothy 2:18).
Let us put all of our faith in Jesus Christ as Savior to save us from the consequences of our sin, since He is the only remedy. And thereafter let us make sure to apply the mortifying power of the Holy Spirit against the flesh and walk in His life-giving power in our lives, so that we walk in sanctification and diligently ensure that we do not “receive the grace of God in vain” (2 Corinthians 6:1). Yet, as even Martin Luther realized, we are at the mercy of our loving Father to supply us with the grace that we need to accomplish all those things as those who are “poor in spirit” (Matthew 5:3) and needy of God’s kindness – which Luther confessed in his last words before dying: Wir sind Bettler, das ist Wahr. (“We are beggars, this is true.”)
Soli Deo Gloria.