High Quality Content by WIKIPEDIA articles! High Quality Content by WIKIPEDIA articles! Shirk is the Islamic concept of the sin of polytheism specifically, but in a more general way refers to worshipping other than Allah, associating partners with him, giving his characteristics to others beside him, or not believing in his characteristics. Within Islam, Major Shirk is an unforgivable sin. According to Islamic texts, anyone who commits shirk cannot be forgiven, Allah forgives any sin except for major shirk. It is the vice that is opposed to the virtue of tawhid, literally "declaring one", often translated into the English term monotheism.