For this reason, many texts in the Quran and sunnah warn against the causes of apostasy and all forms of shirk and disbelief that nullify the declaration of monotheism, “There is no deity worthy of worship except Allah.” In the chapter on rulings concerning the apostate in works of Islamic jurisprudence, the scholars—may Allah have mercy on them—have stated that a Muslim may apostatize from his religion through many different nullifiers. If he falls into them—or into any one of them—he apostatizes from the religion and leaves the fold of Islam, and merely uttering “There is no deity worthy of worship except Allah” will not benefit him. This is because this great declaration, which is the best and most excellent form of remembrance, benefits the one who utters it only when he fulfills its conditions and avoids everything that nullifies it.

There is no doubt that a Muslim derives immense religious benefit from knowing these nullifiers when he seeks through that knowledge to remain safe from these evils and escape those perils. Thus, whoever knows shirk, disbelief, falsehood, and the paths leading to them; detests them, guards himself against them, warns others about them, repels them from himself, and does not allow them to mar his faith—but rather, through knowing them, grows in insight into the truth and love for it, as well as in hatred of and aversion to those evils—will gain benefits and advantages from this knowledge whose full extent is known only to Allah. Allah, Glorified is He, loves for the path of truth to be known so that it may be loved and followed, and He loves for the path of falsehood to be known so that it may be shunned and detested. Just as the Muslim is required to know the path of goodness so that he may follow it, he is also required to know the paths of evil so that he may guard against them. Hence, it is authentically reported in the two Sahīhs that Hudhayfa ibn al-Yamān—may Allah be pleased with him—said: “The Companions used to ask the Messenger of Allah—may Allah’s blessings and peace be upon him—about good, while I used to ask him about evil for fear that it might overtake me.”1 It has likewise been said: