Marriage stands at the intersection of law, culture, and theology as one of humanity’s most enduring institutions. Across civilizations, it has been variously understood as a legal contract regulating rights and obligations, a covenant binding parties, families, communities, and within Christian thought, a sacrament embodying divine grace. This study contends that these dimensions are not discrete or competing categories but complementary layers of a single, coherent reality. Focusing particularly on pluralistic societies such as Nigeria, where civil (statutory), customary and canonical systems operate concurrently, the paper interrogates the fragmentation produced by multiple marriage ceremonies and its implications for legal clarity, cultural integrity, and theological coherence. Through historical, legal, and theological analysis, the essay examines the evolution of marriage from ancient legal codes to contemporary civil and canon law, while engaging Igbo customary practices in Nigeria as a critical case study of communal and symbolic depth. It argues that the separation of marriage into distinct statutory, customary, and canonical rites obscure unity of the marital act. Consequently, it advances a normative framework for a unified marriage ceremony that satisfies statutory legality, respects customary legitimacy, and preserves sacramental integrity. Such integration is presented not merely as administrative reform but as a jurisprudential and theological imperative for the future of marriage.