Summary of answer:
Praise be to Allah
Hijab is a definite obligation enjoined by Allah, may He be exalted, on the Muslim woman. Its obligatory nature is proven from the Qur’an, the saheeh Sunnah, and the consensus of the ummah of all madhhabs and schools of thought; no madhhab differed from that and no faqeeh went against it, and this has been the practice throughout the history of the ummah. Allah, may He be exalted, says (interpretation of the meaning):
“O Prophet! Tell your wives and your daughters and the women of the believers to draw their cloaks (veils) all over their bodies (i.e., screen themselves completely except the eyes or one eye to see the way). That will be better, that they should be known (as free respectable women) so as not to be annoyed. And Allah is Ever Oft-Forgiving, Most Merciful”
“…and to draw their veils all over Juyubihinna (i.e. their bodies, faces, necks and bosoms, etc.) and not to reveal their adornment…”
The duty that is required of every Muslim is to adhere to the obligations of his religion, and to strive to please his Lord and comply with His commands. No one has the right to force a Muslim, whether by means of physical or psychological pressure, to give that up and not obey his Lord.
We have previously discussed the details of hijab as prescribed in Islam in fatwa no. 6991.
It is not permissible for the Muslim woman to go against these requirements, and it is not permissible for her to stay in a place where she is not able to adhere to the manner of dress prescribed in Islam. Rather, if she is faced with pressure in any place, and she is afraid to adhere to hijab or any other symbol of her religion, she must migrate from that place, because migration from such places is obligatory, as we have explained previously in fatwa no. 13363.
Moreover, some Islamic knowledge is obligatory for every Muslim to learn, so it is not permissible for him to be heedless about it or to claim the excuse of ignorance. That includes matters such as knowing about the Oneness of Allah, may He be glorified, and His Lordship and His divinity, and knowing the individual duties of every Muslim man and woman. With regard to such knowledge, it is obligatory for every Muslim to learn it, as we have previously explained in detail in fatwa no. 161081.
So the Muslim should take all possible means and follow every possible path to acquire this kind of knowledge. If he takes such measures but finds that there is pressure on him in some place, that prevents him from learning, then he must also migrate from that place to another place, exactly as we said in the case of the Muslim woman who experiences pressure with regard to wearing hijab as prescribed in Islam: she must migrate to another place where she will be able to obey her Lord and cover her body as Allah wants her to and has made obligatory for her.