Question Summary:
Is it permissible to work for a bank, whose income is reported to be 75% from interest bearing loans?

Question Detail:

Is it permissible while residing in a metropolitan area where there is a tonne of other jobs available, to continue to work for a bank, whose income is reported to be 75% from interest bearing loans. 
Is it permissible to buy a second house on mortgage and put it up for rent and use the rental income to pay the mortgage on such a house. According to my husband, there is perfectly fine and he continues to do so even against my advice for past years. it is an issue that is taking me to the extent of thinking of separating and divorce as my husband has been doing this for  years and I have been advising him with even any islamic references when possible. but to no avail. I feel I cannot continue to be a wife to such a man. Please advise as this is a very contentious and urgent issue in my life. 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
Sister in Islam,
Interest is clearly haram. Consider the following from the Qur’aan and Ahadeeith
 

Allah has permitted trade and forbidden interest (Al-Baqara 275)
 

. O you who believe, fear Allah and give up what still remains of ribā, if you are believers. (Al-Baqara-277)
 

Rasullullah Sallalahu Alaihi Wasalam cursed one who consumes, pays and witnesses interest and he said their all equal (Muslim p27 Qadeemi, Tirmizi p239 H.M.S, Bathlulmujhood p239 maktaba sheikh) 
 
Your aversion to interest is Alhamdulilah a sign of your correct and proper imaan.
In the case of working in a conventional bank, if the banks major source of income is from interest, then it will not be permissible to work there. If one does not have another source of income then, he may continue his employment and make tawba while searching for an alternate job.
As for purchasing homes on interest, it is obviously prohibited.
Sister, while you correctly have an aversion for interest and you are worried about your husband’s income, you should apply wisdom in addressing the issue and correcting him. Do not let this issue lead to a marital problems as this important issue may be diluted in the marital problems and may never be addressed. It may be an idea to obtain literature and CD’s of Ulama on the importance of earning halal and on the prohibition of interest. Also try and leave such literature within the sight of your husband so that it may have an effect on him and prompt him to listen to the talks or read the literature.
It may also be an idea to request the local Alim to advise him or to address the issue in general in his jumma talks or general talks. The most effective way to reform someone is hikmah and diplomacy. Inshallah your purpose will be ultimately achieved. 
 
And Allah Ta’āla Knows Best
Ismail Dawoodjee
Student Darul Iftaa
Zambia
Checked and Approved by,
Mufti Ebrahim Desai.
www.daruliftaa.net