Thanks for the question. Here are four points to consider.
1. The Biblical understanding of Sin is that it is our condition: concupiscence. According to the 2nd Article of Augsburg Confession, sin is not simply a set of actions.
2. The relationship between sin and forgiveness is not that of a tally board that gets wiped clean every so often with forgiveness.
3. We are not in a constant state of flux going from being damned one minute to saved the next.
4. I think there’s a good example of this in the latter part of Hammer of God’s 2nd novella:
Fridfeldt lowered his eyes. It was easy to become disconcerted in the presence of such purposeful and strong-willed people. He sat before all these unruffled and authoritative persons like a pale and spindly school boy. Fortunately, one of the sturdiest among them came to his rescue. “We think a good and Spirit-filled sermon was heard today, Pastor. If you have more of that kind, we should be happy to have you come and read a bit for us at the meetings in Sörbygden. It is more important what is preached than who preaches. What we heard today did us good. It was the true gospel.” “But the Spirit must be present,” spoke up the storekeeper. “And the Spirit flees when we stick to the letter. The Spirit is liberty, but written sermons and ceremonies are the letter that kills.” “The letter that kills is the law,” said Fridfeldt. “That is the clear teaching of Scripture. The law kills by condemning us to death. But printed letters do not kill. The Bible is full of printed letters; it is, nevertheless, full of spirit and life. If someone sits down and prepares a sermon based on Scripture, and writes down the sacred words on paper, it would be strange indeed if the Spirit should leave for that reason. And if one selects good words of Scripture and reads them before the altar as prayers or texts, it is certain that the Spirit can be there too.” He was suddenly aware of the fact that he was defending the liturgy of the church. That had never happened before. But he sensed the danger of a new enslavement to forms developing which would force the spiritual life into an arbitrarily tailored straightjacket, which was both poorer and more rigid than the one that had come down from their forebears. “And since you believe so firmly in the witness of the Spirit in the heart,” he continued, addressing Isaksson, “I can myself testify before my friends here that, as I was reading the sermon in church today, God’s Spirit filled my heart with such light and clarity that I saw truths in the Word that had long been altogether hidden from me.” The other farmer from Sörbygden fingered his heavy gold watch chain and spoke. “It was much like that for me too. I have never before seen the truth about grace and sinful corruption so clearly presented. One toils with the flesh but never gets it put to death. One wonders, then, if perhaps the conversion was not genuine, or if no more grace is to be found. But today I have come to understand that the saving foundation does not lie here” (he beat upon his chest), “but in Jesus only. If He has redeemed my corrupt human nature, I can continue on the narrow way with confidence.” “But a true Christian must nevertheless have a pure heart,” said the housewife from Västergården. The farmer looked at her long and searchingly. “Do you, then, my dear woman, have a pure heart?” he asked. The woman flushed. “If one truly prays God for a clean heart, it is certain that one will receive it.” “Have you asked God to give you a pure heart?” The woman avoided his glance and twisted a bit. “God is almighty,” she said, “and he will answer our prayers. If one prays aright for a clean heart, then one must receive it.” “When were you saved, my friend?” asked the farmer. “Fifteen years ago,” the woman answered, somewhat irritated by all the questioning. Did someone question that she was a child of God? “Then I believe that you have kept praying for a clean heart for fifteen years. But you still have not got it,” said the farmer calmly. “It has been the same way with me. But today I have come to understand that also my unclean heart can stand under grace for Jesus’s sake. So I shall be saved as a sinner, and Jesus only will have the glory.”
“Sinners will not be saved,” said the woman, sharply, “but only he who repents and believes.” “True,” said the farmer, “but to be converted means to take refuge in grace. It is to believe in Jesus, in Jesus only. It is a salvation for sinners. There is no other salvation.” “Do you deny, then, that God can make an evil heart clean?” It was a storekeeper who asked the question. He looked sharply and with distrust at the ones from Sörbygden. “It would be wicked to deny that,” Fridfeldt hastened to answer. “God can do whatever He wills. But it is neither true that God must give a man a clean heart, nor that he must have a clean heart, before he can become a child of God. God saves us by grace, even with our unclean hearts. Our state of grace rests not on our heart, whether clean or unclean, but on the righteousness and merits of Jesus.”
Giertz, Bo; Giertz, Bo (2004-12-29). Hammer of God (pp. 210-213). Fortress Press. Kindle Edition.
Grace and peace,
Pr. Matt Lorfeld