Is this passage talking about a radical change in God's justice itself, or it is a mere change of the covenant condition for justification or righteousness? Exegete Paul's justification doctrine with focus on the immediate context, as much as possible.
[ESV Rom 4:5-8] 5And to the one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness, 6just as David also speaks of the blessing of the one to whom God counts righteousness apart from works: 7“Blessed are those whose lawless deeds are forgiven, and whose sins are covered; 8blessed is the man against whom the Lord will not count his sin.”
(Psalm 32:1-2 Blessed is the one whose transgression is forgiven, whose sin is covered. Blessed is the man against whom the LORD counts no iniquity, and in whose spirit there is no deceit.)
Background on the justice of God and Bible-org article on the verse for education purpose. Exod 23:3; Exod 23:6; Lev 19:15; Deut 1:17; Deut 16:19; Prov 18:5; Prov 28:21; John 7:24; Jas 2:1
[ESV Psalms 10:13] Why does the wicked renounce God and say in his heart, “You will not call 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] 23These also are sayings of the wise. Partiality in judging is not good. 24Whoever says to the wicked, “You are in the right,” will be cursed by peoples, abhorred by nations,
[ESV Prov 11:20-21] 20Those of crooked heart are an abomination to the LORD, but those of blameless ways are his delight. 21Be 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.”