It is a myth that either Paul or David mentions a wrongful justice, or false forgiveness where he is observing the injustice of impropriety and deceit in forgiveness where the person is forgiven without sanctification and repentance, and is free to live in sin. Forgiveness and righteousness are conditional. The thought of God committing injustice, impropriety, is akin to a logical contradiction like a married bachelor or a square circle. God would have no basis to command justice and holiness, if he himself becomes an abomination; in other words, the moral law for man is directly grounded upon the holy perfect nature of God. Where did the thought begin, that says God will never count our sins, or he has forsaken his justice for the sake of mercy, and all past, present, future sins are forgiven in advance, thus legalizing sins?
[ESV Psalms 10:13] Why does the wicked renounce God and say in his
heart, “You will not call to account”?
NLT "... They think, "God will never call us to account."
[ESV Prov 17:15] He who justifies the wicked and he who condemns the
righteous are both alike an abomination to the LORD.
[ESV Prov 24:23-24] These also are sayings of the wise. Partiality
in judging is not good. Whoever says to the wicked, “You are in the
right,” will be cursed by peoples, abhorred by nations,
[ESV Prov 11:20-21] Those of crooked heart are an abomination to the
LORD, but those of blameless ways are his delight. Be assured, an
evil person will not go unpunished, but the offspring of the righteous
will be delivered.
[ESV Exod 23:7] Keep far from a false charge, and do not kill the
innocent and righteous, for I will not acquit the wicked.
[ESV Exod 34:7] keeping steadfast love for thousands, forgiving
iniquity and transgression and sin, but who will by no means clear the
guilty, visiting the iniquity of the fathers on the children and the
children's children, to the third and the fourth generation.”
Jude 4 For certain people have crept in unnoticed who long ago were designated for this condemnation, ungodly people, who pervert the grace of our God into sensuality and deny our only Master and Lord, Jesus Christ.
Rom 3:25 whom God put forward as a propitiation by his blood, to be received by faith. This was to show God's righteousness, because in his divine forbearance he had passed over former sins.
[ESV 2Pet 1:8-10] For if these qualities are yours and are increasing, they keep you from being ineffective or unfruitful in the knowledge of our Lord Jesus Christ. For whoever lacks these qualities is so nearsighted that he is blind, having forgotten that he was cleansed from his former sins. Therefore, brothers, be all the more diligent to confirm your calling and election, for if you practice these qualities you will never fall.
[ESV Ezek 18:20-32] The soul who sins shall die. The son shall not suffer for the iniquity of the father, nor the father suffer for the iniquity of the son. The righteousness of the righteous shall be upon himself, and the wickedness of the wicked shall be upon himself. “But if a wicked person turns away from all his sins that he has committed and keeps all my statutes and does what is just and right, he shall surely live; he shall not die. None of the transgressions that he has committed shall be remembered against him; for the righteousness that he has done he shall live. Have I any pleasure in the death of the wicked, declares the Lord GOD, and not rather that he should turn from his way and live? But when a righteous person turns away from his righteousness and does injustice and does the same abominations that the wicked person does, shall he live? None of the righteous deeds that he has done shall be remembered; for the treachery of which he is guilty and the sin he has committed, for them he shall die. “Yet you say, ‘The way of the Lord is not just.’ Hear now, O house of Israel: Is my way not just? Is it not your ways that are not just? When a righteous person turns away from his righteousness and does injustice, he shall die for it; for the injustice that he has done he shall die. Again, when a wicked person turns away from the wickedness he has committed and does what is just and right, he shall save his life. Because he considered and turned away from all the transgressions that he had committed, he shall surely live; he shall not die. Yet the house of Israel says, ‘The way of the Lord is not just.’ O house of Israel, are my ways not just? Is it not your ways that are not just? “Therefore I will judge you, O house of Israel, every one according to his ways, declares the Lord GOD. Repent and turn from all your transgressions, lest iniquity be your ruin. Cast away from you all the transgressions that you have committed, and make yourselves a new heart and a new spirit! Why will you die, O house of Israel? For I have no pleasure in the death of anyone, declares the Lord GOD; so turn, and live.”
So does God count sins against a believer or not?
Yes certainly, start with the parables and teachings of Jesus. God will judge each according to his works, without partiality. See Rom 2:6-16, Heb 10:26. When reading any verse about forgiveness, we need to pay attention to the context and must read with the harmony of the scripture, rather than ignoring the whole Bible based on a misinterpretation of one verse. (Matt 5:29-30; 2Pet 3:16-17)
[ESV Rev 22:11-12] Let the evildoer still do evil, and the filthy
still be filthy, and the righteous still do right, and the holy still
be holy.” “Behold, I am coming soon, bringing my recompense with me,
to repay each one for what he has done.
[ESV 1Pet 1:15-17] but as he who called you is holy, you also be holy
in all your conduct, since it is written, “You shall be holy, for I am
holy.” And if you call on him as Father who judges impartially
according to each one's deeds, conduct yourselves with fear throughout
the time of your exile,