Sufism, as a mystic sect of Islam, can be defined as a philosophy of inner experience. The process of inner thought and experience plays an important role in sufism. Existentialism is also a philosophy of being. In existentialism being cannot be rationalized; it can be experienced in a personal venture which philosophy is the way to achieve. The aim of this paper is to compare sufi philosophers with theist existentialist philosophers mainly on the concept of person. How religious elements play (...) a role in forming the concept of person in each philosophical system is investigated by means of several basic parameters such as being, existence, transcendent self, despair, death, knowledge and freedom. Both in sufism and theological existentialism a religious significance is given to the concept of existence. In both philosophical systems, the finitude a person experiences in this world drives one to an alienation from one's essential being to the more profound dread of guilt and anxiety, and salvation can be reached by the unification of oneself with God. (shrink)