Предметом Литургики является история православного христианского богослужения.
Православное богослужение есть совокупность молитвословий, песнопений и священнодействий, которые совершаются в Церкви Божией на земле иерархическими лицами, как законными наместниками Христа.
Archbishop Averky (Taushev) (1906–1976) was the fourth abbot of Holy Trinity Monastery (Jordanville, NY). He was born in Imperial Russia, but had to leave the country with his family in the wake of the Russian Revolution. Living in Bulgaria, he was drawn to the monastic life, and soon became a monk and a priest. He taught and ministered in Bulgaria, Czechoslovakia, Yugoslavia, and Germany, before being assigned in 1951 to teach at the Holy Trinity Seminary. He was consecrated a bishop, and after the death of Archbishop Vitaly (Maximenko) became the abbot of the monastery. As abbot, he was also the rector of Holy Trinity Seminary and was heavily involved in the formation of its curriculum and daily life. He was also praised by converts to the Orthodox faith such as Hieromonk Seraphim (Rose) for being a steadfast defender of traditional Orthodoxy. He wrote many commentaries on scripture and other works which are extensively read both in Russia and in the diaspora.