Isomorphism in Nigerian Christian Sermons

Although previous studies of Nigerian Christian sermons have explored their pragmatic, rhetorical, stylistic, and ideological dimensions, relatively little attention has been given to the interaction between syntactic organisation and Information Structure in the construction of theological meaning. This study investigates the isomorphic relationship between syntactic structure and communicative function in Nigerian Christian sermons, focusing on how marked constructions foreground doctrinal messages and guide audience interpretation. Drawing on Information Structure theory, the study integrates syntactic analysis with discourse-functional interpretation to explain how grammatical form encodes informational prominence in sermonic discourse. A qualitative corpus-based design was adopted, using sixty purposively selected syntactically marked clauses extracted from sermons delivered by four prominent Nigerian Christian preachers. The data were analysed for patterns of focus marking, thematic organisation, and form-meaning alignment. Findings show that preposing, topicalisation, existential constructions, clefting, and passivisation function as discourse-organising resources that regulate information flow, enhance theological salience, and improve cognitive accessibility. Preposed and topicalised elements serve as thematic anchors, while existential and cleft constructions foreground doctrinally significant propositions in accordance with Information Structure principles. Passive constructions redirect attention towards outcomes and experiential states by backgrounding agency, reflecting theological orientations centred on divine purpose. Although syntactic form generally aligns with communicative function, contextual factors may occasionally produce subtle mismatches between the two. The study extends Information Structure theory to African religious discourse by demonstrating how syntactic choices operate as strategic resources for organising meaning, reinforcing theological emphasis, and enhancing audience engagement in contemporary Christian preaching.