The Qur'ān says, “Indeed, God enjoins justice and kindness.” (16:90) Given that the context of this verse pertains to the responsibilities of human beings toward their society, the term ‘justice’ should be interpreted as ‘social justice’. Thus, God has ordered human beings to uphold justice.
'Allāma Ṭabāṭabā'ī has said that social justice denotes treating each member of society in accordance with their merit and ensuring everyone receives their rights. This social quality is an obligation that responsible individuals must observe [1]

The establishment of social justice is one of the most important teachings of divine prophets ('a). Hence they strived to explain its essence and scientific principles, inculcate its spirit within humanity, and compel its acceptance as a cornerstone upon which earthly life depends. Anyone with basic knowledge of religious teachings understands that the establishment of social justice enlivens God's religion. 

Thus, until justice prevails, true religion remains incomplete. Similarly, until universal social justice takes root, the fulfillment of religious and legal obligations remain unattained. [2]

The absence of social justice historically has been the cause of most revolutions. Noble-minded reformers have consistently started their movements with the of establishing social justice and eradicating discrimination. The Prophet (ṣ) said that “Justice in social struggle is like a guardian shield which protects people from oppression; and it is like a stable paradise that perpetually bestows its blessings” [3]

Although it is necessary for everyone to respect one another's rights, it is more important for a leader [to respect human rights]. In this regard, Imām 'Alī ('a) told his commanders that neglecting people's rights equates to ruin [4]. Additional, Imām Riḍā ('a) said that the Household (Ahl al-Bayt) of the Prophet (ṣ) are guardians and protectors of the believers' rights [5]

However, it is not solely leaders who must foster social justice; Islām has said both leaders and followers possess rights. Social justice can only thrive when everyone's rights are upheld. Imām 'Alī ('a) said that mutual respect between leaders and followers results in the elevation of righteousness, the revelation of religious principles, and the solidification of just characteristics.[6]

Characteristics of Social Justice

1.    Meritocracy

One of the most important characteristics of social justice is meritocracy, which means entailing the assignment of roles and responsibility based on individual merit. Justice mandates that the most qualified individuals are given precedence for opportunities and higher positions. 

Imām 'Alī ('a) instructed Mālik Ashtar to appoint individuals to different positions in accordance with their merit (Nahj al-Balāgha, letter to Malik Ashtar). The Prophet (s) emphasized that it is treachery to appoint less qualified people to positions of authority [7]

2.    Prioritizing the Rights of the Impoverished and Needy

Another characteristic of social justice is paying attention to the rights of the poor and needy. Injustice is a contributing factor to poverty, which in turn breeds various hardships. Luqman said that of all the bitterness he had encountered, poverty was the harshest. The Prophet (s) said that poverty, pain, enmity, and fire are never trivial [8], and that poverty represents a significant form of death [9]

These reports show that leaders have heavy responsibilities, because the poor need justice more than other people. 

3.    Respecting People's Rights 

When oppression becomes prevalent in society, leaders should not merely distance themselves from it; they ought to stand up and fight for the rights of the oppressed. In fact, all individuals must resist remaining silent when others endure oppression, as passivity equates to complicity in oppression.

Furthermore, not only oppression destroys everything, including culture, economics, wisdom, ability, talent, innovation, etc. but also it is the biggest obstacle to establish justice within society. Imam 'Alī ('a) asserted that ending oppression is a prerequisite for justice.

4.    Equity and Impartiality

It has been reported that one day a rich man and a poor man were sitting next to each other. The rich man pulled his face at the poor man and adjusting his clothes. Observing this the Prophet (ṣ) asked the rich man “Are you afraid that some of his poverty will be transmitted to you?” [10]

The Prophet (s), both in words and acts, paid attention to this important characteristic. For example, when a woman from the Banī Makhzūm tribe committed theft and the people asked the Prophet (s) to judge, her family, who were still influenced by the customs of the class system, considered execution of punishment to be shameful for their aristocratic family. As a result, they started looking for ways to prevent the punishment. To this end, they coerced Usama ibn Zayd, whom the Prophet (s) held in deep affection, to intercede with the Prophet (s) and halt the punishment. However, scarcely had Usama begun to speak when the Prophet (s) grew angry and said no one should stop him from implementing God's laws. Usama promptly sought forgiveness. Later that day, the Prophet (s), aiming to dispel any perception of favoritism, addressed the incident in a speech. He said “Throughout history, tribes and nations declined and vanished due to favoritism in justice’s administration. When both an aristocrat and a commoner committed the same crime, they would punish the commoner while granting impunity to the aristocrat. I swear by the God in whose hands hold my life that I shall spare no one from punishment, regardless of their social standing, whether high or low” [11]

On a different occasion, when Umm Hānī, Imām Alī's sister, went to see him, the Imam gave her twenty dirhams. When she asked her non-Arab bondswoman about her received amount, the female slave said she had also been given twenty dirhams. Incensed by this equality, Umm Hānī confronted her brother, Imam Ali, in protest. In response, the Imam sent her back with these words: “Go back, and may God forgive you. In the Book of God, we have not found any preference for Ishmael over Isaac” [12]

5.    Distinction between the Benevolent and the Malevolent

A leader must avoid treating benevolent and malevolent individuals equally, as this engenders injustice. Imām Alī ('a) instructed Mālik Ashtar to avoid treating benevolent and malevolent individuals equally, because doing so could discourage the benevolent and embolden the malevolent. Instead, everyone should be rewarded according to their deeds.[13]
   

       
          references 

1. (Al-Mīzān fī Tafsīr al-Qur'ān, vol. 24, pp. 243-246).
2. (Al-Ḥayāt, vol. 2, p. 97).
3. (al-Ḥadīth – Riwayāt-e Tarbiyyatī, vol. 2, p. 265). 
4. (Nahj al-Balāgha, letter no. 79)
5. (Musnad al-Imām al-Riḍā, ('a), vol. 1, p. 136). 
6. (Nahj al-Balāgha, sermon no. 216). 
7. (Al-Ta'ajub, p. 59).
8. (Nahj al-Faṣāha, saying no. 252)
9. (Nahj al-Balāgha, saying no. 163).
10. (Majmu'at Waram, vol. 1, p. 214).
11. (Ṣaḥīḥ Bukhārī, vol. 5, p. 152).
12. (Biḥār al-Anwār, vol. 40, p. 106).
13. (Nahj al-Balāgha, letter no. 53). 

As a person who has grown up a Muslim, I don’t understand why this question may come up for some people; can Muslims have fun and joy?

Before anything, Muslims are human beings with the same needs that all human beings have, such as eating, sleeping, working, earning money for a living and enjoying their life. It is after having all these primary needs that they choose to follow a specific framework in their life; Islamic lifestyle.

As far as I have observed and studied the issue of fun, entertainment, and joy in non-Muslim cultures, it is usually based on weekends at bars or nightclubs, spending all time gossiping, chattering or dancing and coming home drunk and tired.

Or some families go out for a family meal at a restaurant. Some may go on a picnic or camping in nature. Some families plan parties at home with friends or relatives.

Another activity which is called fun in non-Muslim cultures is having fun and spending time with the opposite sex. Some youth would like to have their personal vehicles to play their favorite music tracks and hang around with friends in their cars. Staying home and watching movies or playing video games is also another form of entertainment.

Now, let’s see what the status of fun and entertainment is in the Islamic lifestyle! And what the difference between Islamic and non-Islamic lifestyle is.

Do Muslims Have Fun?

There are many verses in the holy Quran that mention this worldly life is nothing but play and diversion [i]. But does it mean that we have to take this life as fun and entertainment? Of course not. The aim of calling this worldly life as play and diversion is to draw our attention towards a more important lifestyle: a useful lifestyle that guides us towards success in this world and the afterlife. Allah says in the Quran:

“Leave alone those who take their religion for play and diversion and whom the life of this world has deceived …” (6: 70).

Therefore this world should not entertain us so much that we forget why we have come to Earth, where we are going after death, and what the whole goal of living in this world is.

The Necessity of Having Fun in Islam

Talking about the goal of life does not mean that Muslims should spend all their time working and praying. There are many narrations that recommend Muslims to divide their day into four parts. Imam Reza (AS) says: “try to divide your day into four parts; one part for praying and communicating with your Lord, one part for earning lawful (Halal) money for a living, one part to communicate with your religious brothers who will help you know your deficiencies, and a part to entertain your soul with lawful pleasure, and in the fourth part you will gain liveliness to fulfill other three duties.” [1]

Therefore Muslims should set aside a part of their time to have fun, rest and have lawful (Halal) pleasure, as well as spend some considerable time with their family, talking to children to find out if they have any issues, reading different books and keeping themselves up to date. Specifying some time to pleasure and entertainment helps people have a more organized plan to fulfill their duties.

A Muslim Has No Spare Time

Muslims should plan their lives in a way that they would find no spare time. Spare time makes people feel useless, and then they would try to find some ways to get rid of those times. That is usually where aimless entertainment enters one’s life.

Allah says in the Quran: “So when you are done, appoint,” (94: 7), that in some interpretations means when you finish one task, you have to start a new one.

That new task might be planned as having fun, of which I will bring some examples later on in this article. So, it is important that Muslims plan their lives in a way that they find no spare or unused time in their day. 

What is Forbidden (Haram) Fun?

The most important point in having fun from the Islamic point of view is that one should choose a sort of entertainment that does not harm one’s self and others.

So if you have a careful look into the Quranic verses that name some kinds of pleasure forbidden, you can realize that those may lead into harm for the person him/herself and people around him/her.

Therefore, any entertainment in which people use drugs or alcohol, such as parties in which alcohol or drugs are used, or even nightclubs and bars that are the exact places for these kinds of entertainment are totally rejected in Islamic lifestyle.

Also, any Entertainment related to gambling is forbidden (Haram), simply because in gambling there is harm for at least one person. Also, all kinds of entertainment that divert our attention from a Godly life are forbidden (Haram).

The type of entertainment that a Muslim chooses should not be against the laws of Islam such as modesty. A Muslim should not have an aimless pleasure and as mentioned in the Quran; “Indeed Allah does not like the boasters.” (28:76)

The least usefulness that a form of entertainment should have for a Muslim is to refresh his/ her soul and to strengthen his/ her body.

See the second part: What is Lawful (Halal) Fun?

 Notes:

[i]“The life of the world is nothing but play and diversion, and the abode of the Hereafter is surely better for those who are God-wary…” (6:32)

 References:

1. Bihar al-Anwar, vol.75, p.346