Do Christians and Muslims Worship the Same God? A Philosophical Investigation

This article examines whether Christianity and Islam worship the same ‘God’ (i.e., the same divine being). While contemporary Roman Catholicism, following Vatican II, maintains that Christians and Muslims ‘adore the one and merciful God’, this position conflicts with the first-millennium Church’s theological witness, which distinguished the Christian God from non-Trinitarian conceptions of divinity. Through philosophical analysis of classical Christian Trinitarian theology (specifically the Conciliar view) and Islamic Tawhid, this article demonstrates that the essential properties attributed to God in each tradition are logically contradictory and mutually exclusive. The Christian conception necessarily includes eternal generation and internal divine relations, while the Islamic conception necessarily excludes such properties as incompatible with Tawhid. Therefore, these traditions refer to, and thus worship, essentially different divine entities, and thus not just that of them assenting to different descriptions of the same being. This conclusion vindicates the position of the early Church and challenges contemporary attempts to harmonise Christian and Islamic theology. Significantly, Eastern Orthodox Christianity emerges as exempt from this philosophical difficulty, providing evidence for Orthodox theological and philosophical superiority over contemporary Roman Catholicism.