Bahrain is the only country that I have known that has given citizenship to a number of expatriates who have been there for a long number of years(some of my friends have also got it) It does not matter which religion you are you dont even have to change your religion.
People have been in Bahrain?oman and UAE far longer than many who have been in Qatar.
I know some well to do Indians who were offered citizenship in Qatar but who refused it point blank.