Fath-Ul-Majeed Sharah Kitab At-Tawheed فتح المجید شرح کتاب التوحیدThis book written by Sheikh Abdur Rahman Ibn Hasan Aal Ash Shaykh gives a clear explanation of the Muslim sound Creed which is the core of the religion of Islam, as the belief in Tawheed [monotheism] is the purpose for which Allah created both mankind and jinn. Thus, those whose belief in Tawheed is corrupt, are not considered Muslims. It is a commentary on The Book of Tawheed written by Sheikh Muhammad ibn Abdul Wahhab.