Sheikh Hamed Al-`Ali, instructor of Islamic Heritage at the Faculty of Education, Kuwait and Imam of Dahiat As-Sabahiyya Mosque, states that: “Whoever commits a major sin is to be treated as a Muslim because a Muslim is not regarded as Kafir (disbeliever) for committing major sins. However, we should advise this person, guide him to the straight path, and warn him against the consequences of committing sins.
However, if you see that staying away from him will benefit in making him give up the sins he is committing, when he gets to know that one of his dear friends has left him because of the sins he is committing and cannot tolerate you staying away from him, then you may stay away from him for a period of time. But if staying away from him will not benefit him, then you should advise him and try as much as you can to put him back on the right track.”
Sheikh Muhammad Iqbal Nadvi, Imam of Calgary Mosque, Canada, and Former Professor at King Saud Univ., Saudi Arabia, adds:
“Basically, what is to be understood here is that Kufr is a matter of faith. The sins cited here are related to the practice of faith. Thus, anyone who commits these sins is still called a Muslim. Only when he denies faith in Allah the Almighty, he can be branded disbeliever.
The duty of other Muslims towards such a person who commits all these sins is to spare no pains in trying to correct and advise him to avoid committing such major and heinous sins. Another thing is that the advice should be offered in private, not in public. Thus, you should commit yourself to bringing this person back to the right track by kind advice.”