One Nature in Worship: The Presence of Non-Chalcedonian Theology in the Liturgy of the Eritrean Orthodox Tewahdo Church

Abstract

This thesis examines how non-Chalcedonian Christology is articulated and preserved within the liturgical tradition of the Eritrean Orthodox Tewahdo Church, with particular attention to the Keddase (Eucharistic liturgy) and the Deggua (liturgical hymnody). Rooted in the Alexandrian theological heritage, the Tewahdo Church confesses the Miaphysite formula mia physis tou theou logou sesarkomene (one incarnate nature of the Word of God) as central to its Christological identity. Rather than transmitting this doctrine primarily through conciliar definitions or systematic theology, the tradition embeds Christological meaning within the structure, language, and performance of worship. Using a liturgical-theological methodology, the study analyses prayers, anaphoras, hymnographic imagery, musical modes, and ritual practices as theological media. The findings show that the Keddase and Deggua function as primary sites of doctrinal continuity, where Christological unity is enacted and internalized through communal participation. The thesis argues that in the Tewahdo tradition, lex orandi, lex credendi is constitutive: worship does not merely reflect belief but actively forms and sustains it. By focusing on Eritrean Orthodox liturgy, the study contributes to Christological and liturgical theology and highlights an often-underrepresented African Christian tradition.