We are all aware that GOD created us and then we sinned and then Jesus came to the earth, died for us on the cross and saved us by his blood. The first event of injustice takes place in the Bible when Cain killed Abel, his brother. And the cause was jealousy. GOD accepted the offerings of Abel for he offered the best to GOD. Cain did the opposite and GOD did not favor him. So Cain got jealous over his brother first, and that made him angry and then he planned to kill his brother and killed him. Cain killing Abel was unjust; and it was caused by jealous. What was the cause of jealousy? It was the negligence of Cain to give the best part to GOD. You can read the full story in Genesis 4.
Most of us Christians do not understand the importance to give the best part to GOD. When we offer the best of us to GOD, that act makes us just. Now think about Abraham. He gave the most beloved of all his life; his son Isaac to GOD. What did GOD do? GOD made him the father of many nations. And what is Abraham considered as? He is considered as the righteous. “So also Abraham “believed God, and it was credited to him as righteousness” (Galatians 3:6 NIV).
In Matthew 19: 16 – 22, we read that the young rich man wanted to go to heaven. He asked Jesus about the ways to get there. Jesus told him to basically follow the commandments. This young man has been doing those things. When Jesus asked him to sell all his possessions and give them to poor, he sadly went away. Why? Because he had great wealth and he would have lost all of it if he did what Jesus said. The problem is, he kept all the commandments because it was not hard for a rich man to stay away from others possessions and respect parents. When Jesus asked him to sell all his possessions, the rich man did not believe in Jesus. If the young rich man had believed in Jesus, he should have done all what Jesus told him.
Remember the thief that acknowledged on the cross that he was a sinner and Jesus was GOD? He thought that what he did all his life was injustice and he believed in Jesus. He received mercy immediately; Jesus promised him that he would be in paradise with Him the very same day.
For me as a Christian, it is these two qualities that are intertwined. You believe in GOD and give your best part to Him. The causes of injustice are doubt and not willing to give Him the best part to God.