To answer this question about wearing Hijab, we should first understand why God has sent down religion to man and why He orders man what to do and what to avoid. 

Imagine a person who invents an electronic device, for example, a computer; he knows how the computer should be used to give the best outcome. Therefore, there is always a manual coming with the computer that tells us how to use it for a better result. So the user uses the manual to keep the computer safe and productive. 

God has created man, and He knows what is good and what is harmful to him/her. He sent the religion and the Quran as a guide for human beings. Following the instructions in the book will lead to the useful, peaceful and productive life of a human. 

Why so many hard rules?

Some people say that being a Muslim is not merely to pray or fast or observe the Islamic clothing rules (Hijab), but it is the faith of a person that makes him/her a true Muslim, and obeying the Islamic rules is not as important as having pure faith in God. But the fact is that reaching such levels of faith is only possible by passing the phase of being in complete obedience to God. 

Islam means submission and being a Muslim means that one accepts to submit to God’s orders. The father of all Muslims, Christians, and Jews according to the Quran is Prophet Abraham (PBUH): “the faith of your father, Abraham. He named you ‘Muslims’ before” (22: 78). Therefore, from the time of Prophet Abraham (PBUH) the followers of all monotheist religions are called Muslims. 

Although some Islamic rules may look hard to obey, the fact is that “Allah desires ease for you, and He does not desire hardship for you” (2: 185), and the rulings of Islam are to make our life easier, not harder. God has provided specific frameworks for us to reach a comfortable, peaceful and prosperous life, and to face fewer challenges in life. One of those rules is observing the Islamic dress code (wearing Hijab).

Our problem is that we can only see limited dimensions of an issue. For example, in case of the Islamic dress code (Hijab), we just see that it may be hard for women to cover up in a specific way. Or they may be unable to present their beauties in the society, while the Islamic dress code (Hijab) is there to make women protected in their social relations. Hijab is for women to be respected and recognized because of their character, beliefs and capabilities, NOT their appearance and physical beauty. It also helps them be less troubled by those men who have sick hearts [i].

Can one be a Muslim and not wear the Hijab?

Before one realizes that Islam is the real truth and as long as people are in search of the truth, there is no blame on them for not being a Muslim and not following the Islamic rules. But, as soon as one understands that Islam is the true religion from God and the most perfect one, then he/she should logically become a Muslim.

After accepting the main principles of Islam (the Islamic axioms), if you have only a few misconceptions about some of the Islamic rulings such as the Islamic dress code (Hijab), it is suggested that you embrace and try to observe all the Islamic rules, especially the Islamic dress code (Hijab).

This is just like taking a prescription from our GP when feel obliged to take all the medicine for a better result without knowing the reason for using some of it. As you start acting according to some of those rules that do not make sense to you, you can begin to study and to understand the reason for some details that may be unknown to you right now. 

When we believe in Islam, we should believe in it as a whole. It is not correct to accept some parts of it and reject the other parts because in that case, the peaceful life that is promised to Muslims by obeying all religious rules will not be reachable. This uncompleted obedience is like a machine that has lost some of its components and does not work properly. A Muslim who does not obey all the rulings still counts as a Muslim but does not gain the entire benefits that Islam can bring to a person with complete obedience. 

Remember again that Islam means being submissive to God’s orders. We always aim to be the best at something that we start. For example, we may strive to be the best in our education or our career. The same should be with our religion so that one day we may enjoy being as friendly to God as Abraham (PBUH). 

“Who has a better religion than him who submits his will to Allah, being virtuous, and follows the creed of Abraham, a Hanif? And Allah took Abraham for a dedicated friend.” (4: 125)

Conclusion

Becoming a Muslim and obeying the Islamic rules has its own adversities, but at the same time, it has many advantages. A real Muslim who does not only stick to apparent rules of Islam and uses the spiritual tips and hints for his/her spiritual growth can reach the most peaceful life; “Look! The friends of Allah will indeed have no fear, nor will they grieve” (10: 62) 

Notes:
[i] Hijab

There is a consensus among almost all Islamic jurists according to which Muslim women are forbidden to marry non-Muslims. This is clearly stated in Surah Baqarah: “do not marry polytheistic men [to your women] until they believe. And a believing slave is better than a polytheist, even though he might please you” (2:221).

This prohibition applies to both temporary and permanent marriage. But what can be the wisdom behind this Islamic rule?

Choosing a Compatible Mate to Marry for Muslim Women

In many narrations (Hadiths) [1] and some verses of the Quran (2:221); (24:26), Muslims are advised to marry those who are equivalent to them. Being equivalent mostly means to be similar in faith and religion; however, it also includes being alike in culture, wealth, education, and family values. Right after stating the prohibition on the marriage with non-Muslims in Surah Baqarah (2:21), the reason behind this is uncovered (2:221).

In this kind of marriage, the Muslim will be most probably influenced by the polytheistic beliefs (which are in direct contradiction to Islamic teachings) of his/her partner. In such a condition, if the Muslim accepts those beliefs, he/she will be surely destined to enter Hell, and even if he/she remains Muslim, the conflicts between the couple will make their life a real Hell [2].

Then, for Muslim women, marrying a non-Muslim man (whether disbeliever (Kafir) or a believer in other Abrahamic religions) is undoubtedly against the divine guidelines and Islamic teachings, therefore, must be avoided.

Marriage Affects One’s Religious Life

As soon as one gets married, he/she is not fully independent anymore to decide for everything in life. Many habits and interests will be influenced by the preferences of one’s partner and even some of his/her beliefs. Getting married to a non-Muslim means to be seriously exposed day and night to the practices and beliefs of a religion other than Islam, or even to feed the mind with anti-religious thoughts.

This might in the first place hinder one from practicing Islam, then make him/her indifferent to Islamic beliefs and principles, and finally end in converting to a non-Muslim! And, women are more prone to this change: “You (Muslim men) are allowed to marry who doubt in their religious beliefs, but Muslim women are not; since the woman is influenced by her husband and he makes her follow his religion” [3].

Islam completes the teachings of the previous religions [4], therefore it does not allow Muslim women, who have taken the straight path with the help of divine guidance, to deviate and join disbelievers (Kafir) or the followers of other religions by getting married to a non-Muslim and consequently to be supervised by non-Muslims and depend upon them.

Fulfillment of the Wife’s Rights in a Marriage

Islam considers certain rights for the wife over her husband. Treating gently, keeping respect, helping in household chores, forgiving her major mistakes, and honoring her are the duties of a husband in Islam [5]. Besides, men are required to pay the marriage portion (Sedaq) and the living expenses (Nafaqah) to their spouses [5].

These rights will be most probably ignored in a marriage with a non-Muslim man of whether an Abrahamic religion or any other religions and this is another reason to ban Muslim women to marry non-Muslims.

Children’s Education and the Following Generations

To many children, fathers are heroes or at least good enough samples to follow in life. To some, fathers are only a member of the family. In any case, fathers play a predominant role in the education of children.

Hence, a non-Muslim father educates children based on his beliefs, and he surely affects the characteristics, attitudes, and religious beliefs of his children and more generally the following generations. This way, Muslim women married to non-Muslims might find their children disbelievers (Kafir) or followers of other religions, which will be really regretful.

Some Rulings …

The only way Muslim women might marry a non-Muslim man is that he converts to Islam before marriage.

If the formula (Nikah) of a marriage contract is pronounced before the conversion of the man, the marriage contract will be void. If the man converts after this void marriage, the formula (Nikah) still needs to be repeated since the man had not been Muslim during the previous formula (Nikah) [i].

Not getting married to a non-Muslim man is such important that if non-Muslim women (whether disbeliever (Kafir) or a believer in other Abrahamic religions) deliberately join Muslims or immigrates to Muslim communities, and if their faith is examined, It is forbidden (Haram) to send them back to their disbeliever family if they want to stay with Muslims. In this case, Muslim women are not any more lawful to their non-Muslim husband, his husband neither (60:10).

Notes:
[i]  See Risalah Amaliyah for more details and the rulings.

References:

1. S. H. al-Amili, “Wasail al-Shia”, vol. 14.
2. A. H. Tayyib, “Atyab-ul-Bayan fi Tafsir-il-Qur'an”, (2: 221).
3. M. B. Majlesi, “Bihar al-Anwar”, vol. 103, p. 377.
4. M. B. Majlesi, “Bihar al-Anwar”, vol. 76, p. 7