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 presentation of the three-year-old Virgin Mary in the Temple by her parents, Saints Joachim and Anna. Celebrated on November 21st, this feast honors Mary's dedication to God and her preparation for her role as Theotokos. According to tradition, Mary was raised in the Temple until her betrothal to Joseph.

A miraculous icon of the Mother of God found by hunters near the roots of a tree in Kursk. Celebrated on September 8th and March 9th, this icon accompanied Russian emigrants and is now in New York. The icon has survived fires, wars, and persecution, and is associated with many miracles. It represents the protection of the Mother of God over the Russian diaspora.

A devotional service of praise consisting of hymns sung while standing ("akathist" means "not sitting"). The most famous is the Akathist to the Theotokos, traditionally sung during the fifth Friday of Great Lent. Akathists can honor Christ, the Theotokos, or various saints. These services are deeply moving expressions of Orthodox hymnography and devotion.

The evening prayer service of the Orthodox Church, traditionally celebrated at sunset. Vespers includes psalms, hymns, scripture readings, and incense. On Saturday evenings, Great Vespers is often combined with the Sunday Divine Liturgy. The service marks the end of the liturgical day and prepares the faithful for rest and reflection.

The first-called apostle and brother of Peter, who brought Peter to Christ. Celebrated on November 30th, Andrew is patron of Russia, Scotland, and Greece. According to tradition, he preached throughout Asia Minor and was crucified on an X-shaped cross, which bears his name. He represents the call to bring others to Christ.

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.