The point at issue here is that felicity—which is the fullness of joy, delight, and pleasure—is not identical with knowledge itself, nor is it gained by knowledge alone. Knowledge is only a prerequisite, and it must be knowledge of Allah and of His command. The Prophet (may Allah bless him and grant him peace) said in the rigorously authenticated ḥadīth:
“Whomever Allah desires good for, He grants him understanding of the religion.”
Accordingly, anyone for whom Allah intends good is inevitably endowed with understanding of the religion; whoever is denied such understanding has not been intended for good. Yet not everyone who possesses understanding of the religion has thereby been intended for good, for understanding must be joined to acting upon it. Thus, fiqh in the religion is a condition for success, but together with knowledge of the Lord, exalted is He, there must also be worship of Him. Bliss and delight arise through this combination; they are not identical with it. These people have erred on both counts—even if the knowledge they speak of were correct and sufficient, which it is not!
For this reason some Muslims have declared: “Faith consists of words, deeds, and adherence to the Sunnah.” By contrast, these thinkers have excluded deeds and have not committed themselves to the prophets’ laws. They possess only a kind of discourse that is insufficient and riddled with error. They claim that the perfection of the soul is for it to become an intelligible intellect that mirrors the existing cosmos.
Because of this, they have disagreed over whether the soul survives after death, adopting three opinions, all attributed to al-Fārābī. Some, such as Ibn Sīnā and his followers, say that both the knowing and the ignorant souls endure. Others maintain that only the knowing soul endures, for it subsists by virtue of its retained intelligibles, whereas the ignorant soul has no abiding knowledge and therefore does not persist. Still others hold that both are annihilated at death—a view espoused by the thoroughgoing negationists among them and by others who deny the resurrection of bodies and souls altogether, or who deny the resurrection