Thus equality is not a condition for justice, rather rights and appropriate dealings is justice. By keeping this meaning of justice in mind, we can easily understand as to why there are rich and poor, long and short, black and white people in the world? Why men are strong and women are weak? There are good reasons and logical explanations. For example, the delicate body of woman is a beauty and the reverse is a defect for her.
Thus Divine justice is that everyone should get his/her rights in proportion to his / her needs and abilities.
It is also important to note that the many cases of injustices we see all over the world is because of favoritism and human unjustness. Allah Subhanahu taala is Just and He will punish such people on the day of judgment for their unfairness in dealings.

The Holy Quran clearly states that Allah’s decisions and dealings are always based on perfect justice. He is the Lord of the universe and He can do everything He likes as there can never be a slightest opposition or resistance against His will, but it is one of His attribute that He is Just (Adil).

Thus He can throw a good man in the hell-fire by His power, but He will never do so because of His perfect personality.
He will pardon many people befitting for the hell-fire because He is compassionate, merciful, and kind, i.e., His mercy outshines His justice. The Prophet has taught us du’a to ask Allah Subhanahu taala, not to deal us with justice but with mercy and leniency.

The Holy Quran clearly states that :

“Allah is never unjust in the least degree” (4:40)

“we shall set up scales of justice on the day of judgment so that not a single soul will be dealt with unjustly in the least.” (21:47)

“Allah Commands justice, kindness and charity to one’s kindred, and forbids indecency and oppression.” (16:90)

This made it very clear that why Shia consider Adl as the basic belief of Islam and why they differ with Sunnis on this issue.

Divine Justice in the Natural systems.

The definition of justice given by Hazrat Ali (as) can precisely be seen in the Divine laws of nature working in the universe.
Scientists have amazingly confirmed that they find everything in its right place. There is nothing in the universe disorderly and haphazard.
Scientists say that there is a precise balance between the sun, ear th and other planets. If this balance is disturbed, the whole solar system will collapse. This balance which is a beautiful demonstration of Divine justice is found in every atom of the universe. As atom is the unit of matter, it means that justice prevails everywhere in the universe.
Professor Haldane, a famous biologist, has written an ar ticle On being the right size. In this interesting article, he proves that every living creature ( man, animals, insects etc.) has the right size, i.e. their bodies fit to their living conditions and circumstances.
Thus the whole universe and its uncountable things are the witnesses of Allah’s adl (Divine justice).

The Holy Quran confirms the scientific view of the universe.

“He has raised the heavens and has set up a standard for everything.” (55:7)