For this reason, whenever our Prophet, peace and blessings be upon him, saw something of this world that pleased him, he would say: “At Your service; indeed, true life is the life of the Hereafter.” (1) That is, “At Your service, in response to You”—so as to restrain the soul’s unruliness and prevent it from being deceived by the worldly pleasures it sees. Thus, he turns to Allah and reminds himself: “Indeed, true life is the life of the Hereafter,” not the life of this world. The Messenger of Allah, peace and blessings be upon him, spoke the truth. By Allah, true life is the life of the Hereafter: it is everlasting life and bliss untainted by anything that spoils it, unlike the life of this world, which is deficient, troubled, and fleeting.

As for curing hearts of the diseases of doubts, the entire Quran is clarification and a criterion by which all doubts are dispelled. The Book of Allah is filled with knowledge and clear exposition that remove the disease of doubts, and with encouragement and warning that remove the disease of desires. Yet we are heedless of this mighty Book, all of which is goodness. The same is true of what is found in the pure, authentic Sunnah of the Messenger of Allah, peace and blessings be upon him.

As for the well-being of the body, its treatment is of two types:

The first type is medicine brought by the Shariah. It is the most complete and most reliable medicine, for it comes from Allah, who created bodies and knows their illnesses and their remedies. The medicine brought by the Shariah is of two kinds:

The first is material medicine, such as the saying of Allah Most High in Surat al-Nahl: “From their bellies comes forth a drink of varying colors, wherein is healing for people.” [al-Nahl: 69] And such as the Prophet’s saying, peace and blessings be upon him, concerning the black seed: “It is a cure for every disease except death.” (2)