Introduction. As a meaningful, structural and stylistic component of the text, contrast reflects the peculiarities of world perception, cognition and evaluation of the phenomena of the surrounding reality. The juxtaposition explicates the linguistic picture of the world. Antonyms play an important role in the organization of opposition techniques. There are no special studies on the topic of antonymy in Mari linguistics, and there are no dictionaries of antonyms. All this determines the relevance of this topic. The purpose of the work is to identify and describe the functions of antonyms in the texts of Mari prayers. Materials and methods. Texts of prayers of the Mari ethnic religion from published sources, funds of the Mari Research Institute of Language, Literature and History named after V. M. Vasilyev, and the National Corpus of the Mari language are used as objects of analysis. The work used a descriptive and analytical method, contextual and semantic-stylistic analysis, and the method of semantic oppositions. Research results, discussion. In Mari prayer texts, antonyms serve as a sharp contrast. The simple (monomial), polynomial and expanded antithesis, as well as the usual and occasional antithesis, expressively distinguish words and phrases that are in antonymic relations. A simple antithesis in sacred texts realizes its semantic and stylistic potential at the sentence level. The polynomial antithesis carries a significant semantic load at the level of a complex syntactic whole and text, participates in the organization of its structure. The use of antonyms in prayer texts has a conceptual semantic meaning of contrasting evil and good principles. Conclusion. The antithesis in Mari sacred texts indicates sharply opposite social phenomena, is used in contrasting depictions of natural phenomena, and also expresses the meaning of generalization, constancy of phenomena, and action over time. The technique of sharp contrast indicates the evaluative and emotional nature of the statement, creates vivid images.