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.

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 "Feast of Feasts" celebrating Christ's Resurrection from the dead. The most important celebration in the Orthodox Church, Pascha determines the date of all moveable feasts. The service begins with the joyful midnight proclamation "Christ is Risen!" and continues with the Divine Liturgy of St. John Chrysostom.

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 sacrament of sealing with the Holy Spirit, administered immediately after baptism in the Orthodox Church. The priest anoints the newly baptized with holy chrism (myrrh) on the forehead, eyes, nostrils, ears, lips, chest, hands, and feet, saying "The seal of the gift of the Holy Spirit." This sacrament completes baptism and grants the fullness of the Holy Spirit, enabling the person to participate fully in the life of the Church. It corresponds to the Western sacrament of Confirmation but is given to infants.