Romans 3:5-6

3:5 But if our unrighteousness demonstrates the righteousness of God, what shall we say? The God who inflicts wrath is not unrighteous, is he? (I am speaking in human terms.) 3:6 Absolutely not! For otherwise how could God judge the world?

Romans 3:25-26

3:25 God publicly displayed him at his death as the mercy seat accessible through faith. This was to demonstrate his righteousness, because God in his forbearance had passed over the sins previously committed. 3:26 This was also to demonstrate his righteousness in the present time, so that he would be just and the justifier of the one who lives because of Jesus’ faithfulness.