Adikia means unrighteousness. It is the opposite of righteousness. In Romans 1:29 it is said we are filled with unrighteousness and therefore we are the opposite of Jesus of whom we read in 1 John 2:1 My little children, I am writing these things to you so that you may not sin. And if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous;
The simplest meaning of righteous is “one who is such as he ought to be” . Something righteous is what God intended when he dreamed it up. The old Greeks even described a fruitful field as being “righteous”. For those of you who are interested in such things, there is a classic line in the movie “Ferris Bueler’s Day Off” in which the school secretary is trying to explain Bueler’s popularity to an increasingly frantic school principal. WARNING there are words that may be objectionable- “he’s very popular Ed. The sportos, the motorheads, geeks, sluts, bloods, wastoids, dweebies, dickheads – they all adore him. They think he’s a righteous dude.” So Ferris was liked by everyone which meant he was non judgmental and cared about all kinds of people . Hence he was popular. Compare that to Jesus, the only truly righteous man. and how his righteousness caused hatred and division among the unrighteous. He was so popular in some ways that he had to be killed. The principalities and powers could not abide him because every word and action of his showed their unrighteousness.
Our unrighteousness is an overarching condition that shows itself in all kinds of actions and inactions; attitudes and ideas. Paul lists them and we will check them out.