Russian, Church Slavonic and the Orthodox Liturgy

The Russian Orthodox Church's traditional liturgy is conducted not in modern Russian but in Church Slavonic, a conservative liturgical register descended from Old Church Slavonic, the language Cyril and Methodius's ninth-century mission first used to translate Byzantine Greek scripture and liturgy for Slavic-speaking converts, a distinction comparable to Latin's continued liturgical role in Catholicism after vernacular languages had otherwise diverged from it considerably.

Modern Russian-language Bible translations exist and are used for study and some non-liturgical contexts, but full vernacular liturgical reform, comparable to the Second Vatican Council's shift toward vernacular Catholic Mass, has not been formally adopted by the Russian Orthodox Church, whose leadership has generally treated Church Slavonic's archaic register as integral to liturgical solemnity and continuity rather than a barrier to comprehension requiring correction. Russian itself, rather than its liturgical Slavonic register, has become the working administrative and theological language of the modern Russian Orthodox Church's institutional life, seminaries and public commentary, including Patriarch Kirill's own extensive modern Russian-language writing and preaching.