The celebration of Christ's ascension into heaven forty days after His Resurrection, witnessed by the Apostles. This moveable feast always falls on a Thursday and marks Christ's return to the Father and His promise to send the Holy Spirit. The feast emphasizes both Christ's divine nature and His continued presence with the Church.

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 morning prayer service of the Orthodox Church, traditionally celebrated at dawn. Also called Orthros in Greek tradition, this service includes the reading of the Gospel, the Great Doxology, and numerous psalms and hymns. Matins prepares the faithful for the day and is often celebrated immediately before the Divine Liturgy on Sundays and feast days.

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 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.