Romans 3:5

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.)

Romans 3:25

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.