Ayatullah Dastghaib has exhaustively explained the phenomenon of sin, the classification of sins, and the necessity of avoiding them. He has also described fifty different types of Greater Sins. See also part I and III of this book. About sins and particularly the greater sins (Gunah-e-Kabira). Covers sins such as association with God (Shirk), fornication, drinking alcohol, and gambling. Volume I: http: //www.al-islam.org/greater-sins-volume-1-ayatullah-sayyid-abd-al-hu... 5] Volume III: http: //www.al-islam.org/greater-sins-volume-3-ayatullah-sayyid-abd-al-hu...