The descent of the Holy Spirit upon the Apostles fifty days after Pascha, marking the full revelation of the Holy Trinity and the beginning of the Church's mission in the world. During Vespers, special kneeling prayers are offered and the church is adorned with greenery. This feast celebrates the completion of Christ's saving work and the outpouring of the Holy Spirit upon all believers. From this day forward, the Sundays of the year are numbered from Pentecost, signifying the continual life and growth of the Church in the grace of the Spirit.

The central worship service of the Orthodox Church, celebrating the Eucharist (Holy Communion). Usually celebrated on Sundays and feast days, the Divine Liturgy consists of the Liturgy of the Word (scripture readings) and Liturgy of the Faithful (Eucharistic prayer and communion). The most common forms are the Liturgies of St. John Chrysostom and St. Basil the Great.

The Great Prince of Kiev who brought Christianity to Russia in 988 AD. Celebrated on July 15th, St. Vladimir's conversion and baptism of his people established Orthodox Christianity as the foundation of Russian civilization. His feast honors both his personal transformation from pagan ruler to Christian saint and his role in spreading the Orthodox faith.

The "falling asleep" and assumption of the Virgin Mary into heaven. Preceded by a two-week fast, this feast on August 15th celebrates Mary's death and her bodily assumption. Orthodox theology teaches that Mary experienced death but was immediately raised and taken to heaven, where she intercedes for all Christians.

A lengthy service combining Vespers and Matins, traditionally celebrated on the eve of Sundays and major feasts. The All-Night Vigil includes the singing of "Lord, I Call," the Magnificat, the Great Doxology, and numerous psalms and hymns. This service prepares the faithful spiritually for the upcoming feast.

The revelation of Christ's divine glory to Peter, James, and John on Mount Tabor. Christ appeared in brilliant light alongside Moses and Elijah, and the Father's voice proclaimed "This is My beloved Son." Grapes and other fruits are traditionally blessed on this feast, celebrated on August 6th.