for oneself—these are realities distinctive of faith. Whoever does not possess them is not truly among the believers, even though he may be a Muslim. The same applies to his heart trembling when Allah is mentioned, and to his faith increasing when His verses are recited to him.

If it is asked, “Is lacking this faith a sin?” the answer is:

If the revelation making it obligatory has not reached a person, his failure to fulfil it is not a sin. But if that revelation has reached him and he does not act upon it, his failure is sinful, provided he is capable of fulfilling it. Many people—or most of them—do not possess these detailed aspects of faith, although they fulfil the obedience required in Islam, and when they commit sins, they repent and seek forgiveness for them. They do not know that these realities of faith within the heart are obligatory, or even that they belong to faith. Indeed, many among them who know of these realities consider them recommended, supererogatory acts, if they acknowledge their obligation.

“Islam” thus encompasses someone who outwardly professes Islam but possesses no faith at all: the outright hypocrite. It also encompasses someone who outwardly professes Islam and has a general inward belief, but does not fulfil everything obligatory in either respect. These are the defiantly disobedient, each of whom may possess a trait of hypocrisy. It also encompasses someone who fulfils the requirements of Islam and the faith they entail, but does not fulfil obligatory faith in its entirety. Such people are not defiantly disobedient people who neglect an outward obligation or commit an outwardly forbidden act. Nevertheless, they have neglected some obligatory realities of faith—knowledge and deeds of the heart, followed by actions of some bodily faculties—for which they are blameworthy.