Her brother’s wife mistreats her because she is religiously-committed and she hates her

Praise be to Allah.

Firstly: 

With regard to one who does not pray, we have explained the ruling on that, and stated that some of the scholars – who expressed the correct view – have ruled that such a person is a kaafir and it is not permissible to marry such a person or to remain married to him, and that meat slaughtered by him is haraam, and so on. We have discussed these rulings in detail. Please see questions no. 34795 and 20059. 

Secondly: 

With regard to your brother’s wife making fun of those who are religiously-committed and insulting them and mocking them, she should understand that by doing these things she is in serious danger, and that these actions may put her beyond the pale of Islam. 

Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked about the ruling on making fun of those who adhere to the commandments of Allaah and His Messenger (peace and blessings of Allaah be upon him)? 

He replied: Making fun of those who adhere to the commandments of Allaah and His Messenger (peace and blessings of Allaah be upon him) because of their commitment is haraam and is very dangerous and serious, because there is the fear that his hatred for them may be based on hatred of what they are adhering to, namely the religion of Allaah. In that case mocking them is mocking the path that they are following. They are like those of whom Allaah says (interpretation of the meaning): 

“If you ask them (about this), they declare: ‘We were only talking idly and joking.’ Say: ‘Was it at Allaah, and His Ayaat (proofs, evidences, verses, lessons, signs, revelations, etc.) and His Messenger that you were mocking?”

Make no excuse; you disbelieved after you had believed’”

[al-Tawbah 9:65-66]

These words were revealed concerning some of the hypocrites who said: “We have never seen anything like these reciters – meaning the Messenger of Allaah (peace and blessings of Allaah be upon him) and his companions – they are the most greedy, the most false of speech and the most cowardly in battle.” Then Allaah revealed this verse concerning them.  

Those who make fun of the followers of truth because they are religiously-committed should beware, for Allaah says (interpretation of the meaning): 

“Verily, (during the worldly life) those who committed crimes used to laugh at those who believed.

30. And, whenever they passed by them, used to wink one to another (in mockery).

31. And when they returned to their own people, they would return jesting;

32. And when they saw them, they said: ‘Verily, these have indeed gone astray!’

33. But they (disbelievers, sinners) had not been sent as watchers over them (the believers).

34. But this Day (the Day of Resurrection) those who believe will laugh at the disbelievers

35. On (high) thrones, looking (at all things).

36. Are not the disbelievers paid (fully) for what they used to do?”

[al-Mutaffifeen 83:29-36]

Majmoo’ Fataawa al-Shaykh Ibn ‘Uthaymeen, 2/question no. 236. 

Insulting a Muslim is a major sin, especially if one insults him for being religiously committed and righteous. There is the fear that the one who does this may fall into apostasy as stated above with regard to mocking them. 

It was narrated from ‘Abd-Allaah ibn Mas’ood (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “Insulting a Muslim is immorality and killing him is kufr.” 

Narrated by al-Bukhaari, 48; Muslim, 64. 

Al-Nawawi said: 

In Arabic the word sabb (translated here as insulting) means slandering a person and speaking of his honour in a disparaging fashion. And fisq (translated here as immorality) means going out; in sharee’ah terminology it means going out of obedience (i.e., transgressing the bounds of obedience). 

With regard to the meaning of the hadeeth: Insulting a Muslim for no reason is haraam according to the consensus of the ummah, so the one who does that is a faasiq as the Prophet (peace and blessings of Allaah be upon him) said. 

Sharh Muslim, 2/53, 54. 

We advise you to continue advising her, and if that is via your brother, that will be better. Tell him of the Islamic rulings on what she is doing, and encourage him to guide her by whatever means he can. 

We do not advise you to sit with her unless she repents and turns back to her Lord. We fear that you may react towards her, and we fear that she may increase in sin every time she sees you or sits with you. 

Allaah says (interpretation of the meaning): 

“And when you (Muhammad) see those who engage in a false conversation about Our Verses (of the Qur’aan) by mocking at them, stay away from them till they turn to another topic. And if Shaytaan (Satan) causes you to forget, then after the remembrance sit not you in the company of those people who are the Zaalimoon (polytheists and wrongdoers)”

[al-An’aam 6:68]

But if you speak to her and do not shun her, that may be more beneficial for her because it may soften her heart. You can limit it to greeting and welcoming her, and asking how she is, without indulging in any arguments with her that may lead her to do something haraam. 

Do not forget – as well as doing what you can to advise her – to pray that she may be guided aright. 

And Allaah knows best.