There are different religions in the world. The followers of these religions are different from one another in basic characteristics.
If you have to do business in a Muslim country or a city, you have to understand Islam, at least its basics so as to do better with your business. It is not the same as you do business in another country where another religion is in majority.
Muslims eat halal food so the first thing you must do is to get a halal certificate Singapore if you are in Singapore. If you are in another city, get a halal certificate for your business from the local government. This certificate is a must if you are to sell edibles to the Muslims. They only eat halal food.
A halal certificate ensures that you follow all the procedures and laws of sharia to use halal food items in your products.
Besides, you have to understand how Muslims marry, how what type of dressing they prefer, what are their special days, and so on. This will help you improve your business processes and to offer them with the products they cannot resist.
Not understanding your target audience and their religion is one of the biggest mistakes that businesses make. Make sure you do not do it.