This article explores the theological foundations of Siti Musdah Mulia's gender equality thought amidst the dominance of patriarchal and androcentric religious interpretations. This research aims to address the academic gap in previous studies, which tend to be polarized on aspects of legal products (fiqh) and sociological impacts, while neglecting the philosophical-theological basis of Musdah's thinking. Employing a qualitative literature review method with a philosophical approach and a gender perspective, this research proposes the thesis that, for Musdah Mulia, patriarchy constitutes a serious theological flaw akin to veiled shirk (associating partners with God). The findings indicate that Musdah positions Tawhid (Divine Oneness) as the central analytical framework; the absolute acknowledgment of God's oneness logically necessitates the abolition of all forms of human enslavement and domination. Through a humanist-feminist approach, Musdah deconstructs gender-biased interpretations of crucial verses such as QS An-Nisa: 34, asserting that leadership (qiwamah) is a competency-based function, not a natural right of men, and firmly rejecting the legitimacy of domestic violence. This thought affirms that the struggle for gender equality is a manifestation of a Muslim's purification of faith (aqidah).