The second ‘Usul ad-Din is Adalat (Divine Justice). One of the common 99 Beautiful Names of Allah is Al-Adl (the Just). He gives justice and through Him justice is defined and understood since He is the perfection of justice. Numerous verses in the Qurʾan underscore the belief in Adalat. For instance:
“Say: ‘My Lord has enjoined justice’” (Qurʾan 7:29)
Good actions are rewarded and evil doings are punished justly.
In the teachings of Shi’a Islam, justice is the framework within which Allah acts, and so Allah cannot act unjustly. Allah cannot reward or punish human beings for something they did not do. Similarly, Allah does not force people to act rightly or wrongly. Human beings are free to select their own actions. If Allah acted on a whim and judged people without any concept of justice, then human beings would never know how to live according to Allah’s guidance and do what is right. Hence it is logical that Allah acts according to those standards.
Allah has made His laws clear in the Qurʾan and through the teachings of His messengers what constitutes good and bad actions. He has taught human beings the standards of justice, both through the revelations that He has sent to the earth and through our capacity to reason. Thus humans have the freedom to act according to those standards of justice, or to rebel and act unjustly.