Church Slavic

Church Slavic (Church Slavonic) is used today as a liturgical language by the Russian, Serbian, Bulgarian, Ukrainian, Macedonian, and other Eastern Orthodox churches, and by some Eastern Catholic churches, in Russia, Ukraine, Belarus, Serbia, Bulgaria, North Macedonia, and Orthodox communities abroad. It is no one's native language.
Church Slavic grew out of Old Church Slavonic, the first written Slavic language. In the 860s the missionary brothers Cyril and Methodius translated the Bible and liturgy into the Slavic dialect of the Thessaloniki region and created the Glagolitic alphabet; the Cyrillic alphabet was developed soon afterward in Bulgaria. Over the centuries, local forms of Church Slavic developed in Russia, Serbia, and elsewhere, and it strongly influenced the vocabulary of Russian and other Slavic literary languages.