EN
The development of the Muslim society in Northern Nigeria is often seen as a constant struggle of “scripturalist” Islam against allegedly “non-Islamic” influences. A person’s claim to Islam can be challenged on various levels. The most serious is takfir, a declaration that the supposed Muslim is guilty of kufr or unbelief. Another form of condemnation is tabdi´, the accusation of bid’a or “reprehensible innovation”. The third form of condemnation, weaker than either takfir or tabdi´, is accusation of fisq, that is immorality or sin in matters of belief. The question “who is a Muslim” has been a central point of conflict in Nigeria for centuries. In this article, I have shown that the tension between orthodox theology and popular religion will not be easily resolved.