…they were following the creed of Abraham, the creed of pure monotheism and exclusive devotion to Allah. What, then, is this creed that our Prophet—blessings and peace be upon him—was commanded to adopt and that we were likewise ordered to follow? We must learn it, for every Muslim is obliged to know what Allah has made mandatory so that he may fulfill it and avoid neglect. Mere affiliation without knowledge is not enough. It will not suffice to claim Islam while being ignorant of its essence, of what nullifies it, of its rites and rulings. Nor is it acceptable to claim adherence to the creed of Abraham while being unable, when asked, to explain it. This is impermissible. One must know it well, follow it with clear insight, and omit nothing from it. (14) The phrase “that you worship Allah, devoting the religion sincerely to Him” encapsulates the creed of Abraham: worship Allah while purifying the religion for Him alone. It unites two requirements—worship and sincerity. Whoever worships Allah without sincerity, his worship amounts to nothing. A person may worship Allah, fast, perform the pilgrimage, pray, make ʿumrah, give charity and alms, and engage in many acts of obedience; but if he does not carry them out sincerely for Allah—whether he does them for show or to earn a reputation, or if he…