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 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 commemoration of the finding of Christ's Cross by St. Helena and its elevation by St. Macarius for veneration. Celebrated on September 14th, this feast is both joyful (for the Cross's discovery) and solemn (remembering Christ's suffering). Flowers and basil are often blessed, and a strict fast is observed.

The first Orthodox martyrs in Alaska, killed while bringing Christianity to native peoples. Celebrated on July 2nd, these monks were part of the original mission to Alaska and were martyred by hostile natives who later converted to Orthodoxy. They represent the sacrifice required for missionary work and the eventual triumph of the Gospel message.

The 14th-century monk who founded the Trinity Lavra and renewed Russian monasticism. Celebrated on September 25th, Sergius established the monastery dedicated to the Trinity and inspired a spiritual revival in Russia. He blessed Prince Dmitri before the Battle of Kulikovo and represents the harmony between contemplative life and national service.

The Apostle and Evangelist John, author of the Fourth Gospel, three Epistles, and Revelation. Known as "the Theologian" for his profound spiritual insights and "the Beloved Disciple" for his closeness to Christ. Celebrated on May 8th, his feast honors his unique witness to Christ's divine nature and his care for the Theotokos.

The commemoration of the Virgin Mary's miraculous appearance in Constantinople, when she spread her veil over the praying Christians to protect them from enemies. Celebrated on October 1st, this feast is especially beloved in Slavic Orthodox churches. It emphasizes the Theotokos's continuing intercession and protection of the faithful.