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 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 midpoint between Pascha and Pentecost, celebrated on the Wednesday of the fourth week after Pascha. This feast commemorates Christ teaching in the Temple during the Feast of Tabernacles, offering "living water" to those who believe. The day connects Christ's Resurrection with the coming gift of the Holy Spirit, emphasizing continuous spiritual refreshment.

The "Apostles to the Slavs" who brought Christianity and literacy to Slavic peoples in the 9th century. Celebrated on May 11th, these brothers created the Glagolitic alphabet and translated the Bible and liturgy into Old Church Slavonic. Their missionary work established Orthodox Christianity among the Bulgarians, Moravians, and other Slavic nations.