Evil people do not understand God's justice, BUT... those who (actually) follow the Lord... completely understand. (Proverbs 28:5)

My people are fools; they have not known Me. They are foolish children, without understanding. (Jeremiah 4:22)

For they don't understand the way of the LORD, the justice of their God. (Jeremiah 5:4)

But I tell you that men will give an account on the day of judgment for every careless word they have spoken. - Jesus (Matthew 12:36)
 
For we must all stand before Christ to be judged. We will each receive "whatever we deserve" for the good... or evil we have done in this earthly body. (2 Corinthians 5:10)