'Unrighteous' in the Bible

But if our unrighteousness commend the righteousness of God, what shall we say? Is God unrighteous who taketh vengeance? (I speak as a man)

and no longer lend your faculties as unrighteous weapons for Sin to use. On the contrary surrender your very selves to God as living men who have risen from the dead, and surrender your several faculties to God, to be used as weapons to maintain the right.

What can we say, then? God is not unrighteous, is he? Of course not!