Divine Justice (Al-Adl) is the belief that God is Just and does not commit any act of injustice towards any human beings.
It is one of the Five Pillars of Faith in Shi'a Islam.
The belief means that God does not punish people who have obeyed and worshipped him, and does not reward people who have disobeyed Him. This is because injustice is a result of ignorance and the lack of wisdom, all of which cannot be true of God, the Most Knowledgeable, the Most Powerful and the Most Wise.
God has given humans the ability to differentiate good from evil, which in the Qur'an is referred to as 'fitra'.
Humans are born with this ability, and even if a human does not follow a religion, he or she is able to understand that kindness is good and cruelty is evil. Humans also have the ability to choose their actions, so they can do good deeds or evil deeds.
The Justice of God can be proven by the fact that He has given mankind the ability to know good from evil and the ability to choose between them.