Is it permissible to marry an Ismaili girl or to give a girl in marriage to an Ismaili young man, taking into account that they do not perceive a clear doctrinal difference and affirm that they perform the pillars of Islam like the Sunnis, and that the difference lies in non-essential matters? And what are the questions that should be asked to ascertain the reality of the essential doctrinal differences?

The Ismailis are an esoteric sect that conceals itself behind the pretense of allegiance to the Household of the Prophet (Ahl al-Bayt). In reality, their aim is to demolish the doctrines of Islam. Among their factions are the Bohras, the Nusayris, and the Druze. The disagreement with them is not over minor issues but over fundamental matters that undermine faith and lead to disbelief (kufr). Therefore, it is impermissible to marry them, based on the words of Allah Almighty: "And do not marry polytheistic women until they believe. And a believing slave woman is better than a polytheistic woman, even though she might please you. And do not marry [your women] to polytheistic men until they believe. And a believing slave is better than a polytheist, even though he might please you. Those invite to the Fire, but Allah invites to Paradise and forgiveness by His permission. And He makes clear His verses to the people that perhaps they may remember." (Quran 2:221). It is most likely that anyone affiliated with them adheres to their esoteric, disbelieving doctrine. There is no need to question them to ascertain their beliefs, as they may resort to taqiyya (religious dissimulation). Ibn Taymiyyah explicitly stated that the Ismailis and Nusayris are disbelievers, detached from every religion.