Allah, subhanahu wa ta’ala, has commanded the Muslim: “Call men unto the path of your Lord by wisdom and goodly counsel. Present the cause to them through argument yet more sound” (Qur’an 16: 125). Da’wah is the fulfilment of this commandment “to call men unto the path of Allah.” Besides, it is the effort by the Muslim to enable other men to share and benefit from the supreme vision, the religious truth, which he has appropriated. In this respect it is rationally necessary, for truth wants to be known. It exerts pressure on the knower to share his vision of it with his peers. Since religious truth is not only theoretical, but also axiological and practical, the man of religion is doubly urged to take his discovery to other men. His piety, his virtue and charity impose upon him the obligation to make common the good which has befallen him.