This paper advances marginality as a reimagined mode of Christian existence with decisive implications for public theology. It begins with a historical-theological diagnosis of Christianity's long-standing proximity to political power, where church-state symbioses, cultural dominance, and moral majoritarianism have frequently positioned Christianity within hegemonic arrangements. This analysis is not a neutral historical account, but theological evidence of a loss of critical distance from power and epistemic distortions that follow from such proximity. Against this backdrop, the paper offers Christology as a normative criterion for reimagining Christian existence. Drawing on biblical patterns associated with Jesus' refusal of coercive authority, his resistance to political messianism, and the cruciform shape of discipleship, it argues that Christian identity is called into a posture of non-belonging with respect to dominant political and symbolic orders. Marginality is thus reclaimed not as a historical datum or a romanticised condition of exclusion, but as an ontological and epistemological reorientation shaped by Christological judgment. On this basis, the paper develops a constructive framework for theology by clarifying the conditions under which theological speech can be truthfully public. It argues that public theology formed through unexamined proximity to power risks functioning as moral legitimation, whereas a theology appropriately public requires an epistemic posture marked by distance from privilege and sustained by critical accountability. From such a posture, public theology is better positioned to engage contested public realities - including the issue of inequality - without becoming hegemonic authority. By articulating marginality as a constitutive dimension of reimagined Christian existence, the paper offers a conceptual grammar for public theology that is neither hegemonic nor withdrawn, but capable of credible engagement with the public square.