Original sentence: He started a reform movement in the remote, sparsely populated region of Najd, advocating a purging of widespread practices such as veneration of saints and pilgrimages to their tombs and shrines that were practiced by the people of Najd, but which he considered idolatrous impurities and innovations in Islam (bid'ah)
Edited sentence: He started a reform movement in the remote, sparsely populated region of Najd, advocating a purging of widespread practices such as veneration of stones,trees,caves, praying to saints and pilgrimages to their tombs and shrines that were practiced by the people of Najd, but which he considered idolatrous impurities and innovations in Islam (bid'ah)