This paper aims to investigate the debates on religious coexistence within an Islamic state in Egypt, which experienced the actualization of various political streams, including Islamic political movements, through the 2011 Revolution. The Islamization of the state is a serious issue for this country, where a large minority of Coptic Christians and other religious minorities coexist. First, the author attempts to clarify the different visions of the state envisaged by various political streams through the analysis of such materials as Egypt's 2012 Constitution and the program of the "Freedom and Justice Party". Whether a "civil state" is compatible with religiosity becomes a point of contention here. Second, the author examines arguments over religious coexistence among Egyptian intellectuals belonging to the moderate Islamic stream. Moderate Islamic intellectuals have made attempts to theorize equality between Muslims and non-Muslims within an Islamic state, based on the articulation of two concepts, "Islamic citizenship" and "civilizational Islam". Islamic citizenship imposes a set of rights and obligations corresponding to a person's religious affiliation, while respecting the religious autonomy of each citizen. The latter part of this paper focuses on the thoughts of an Egyptian Islamic thinker and international lawyer, Salīm al-'Awwā. Al-'Awwā postulates the enhancement of such rights and obligations by establishing them in a constitution. Al-'Awwā proposes that a general principle for dealing with non-Muslim problems that cannot be solved in terms of brotherhood among compatriots should be humanistic brotherhood. The establishment of relationships among citizens in both the religious and judicial frameworks constitutes the characteristic features of al-'Awwā's idea.