contain these two foundations: affirmation of the truth and love for it. The former is the foundation of speech, and the latter the foundation of action. Perfect love, when accompanied by ability, necessarily entails bodily activity in the form of outward speech and action, as explained above. Whoever regards knowledge and affirmation alone as necessarily producing everything encompassed by the term faith, and everything called faith, is mistaken. Rather, both knowledge and love are essential.
Knowledge is a prerequisite for loving the beloved, just as life is a prerequisite for knowledge. Yet knowing something and affirming its existence do not necessarily entail loving it, unless there is something within the lover that draws him to what he knows and gives him reason to love it. Thus, a person affirms the existence of many things and knows them while hating them. For example, he affirms the existence of devils and disbelievers while hating them. Merely affirming something’s existence does not entail loving it.
Allah, glorified is He, however, deserves in Himself to be loved and worshipped, and His Messenger deserves to be loved for His sake. Hearts possess an innate disposition that calls for loving and obeying Him, just as they possess a disposition that calls for knowing Him and affirming belief in Him. Whoever affirms belief in Him and His Messenger but does not love Him and His Messenger is not a believer until, alongside that affirmation, he also possesses love for Him and His Messenger.
When affirmation of belief in Him and love for Him are established in the heart, the body must necessarily respond with the outward words and deeds that they entail. The words and deeds manifested by the body are the necessary consequence of what is in the heart, its evidence and its effect. Likewise, the body’s words and deeds also influence what is in the heart. Each thus influences the other, but the heart is the root, and the body its branch. The branch draws sustenance from its root, while the root is strengthened and made firm by its branch. This is like the tree used as a parable for the declaration of faith. He says: