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.

Brief prayer services traditionally celebrated at specific times of day: First Hour (6 AM), Third Hour (9 AM), Sixth Hour (noon), and Ninth Hour (3 PM). Each Hour includes psalms, troparia, and prayers appropriate to that time of day. These services sanctify the day and connect us to Christ's Passion, as they commemorate specific moments in His crucifixion and death.

The day after Pentecost, continuing the celebration of the Holy Spirit's descent upon the Church. Also called 'Trinity Monday,' this feast honors the Third Person of the Trinity specifically. Many Orthodox churches hold special services with kneeling prayers, emphasizing the ongoing work of the Spirit in the Church and in believers' lives.

The Tuesday after Pentecost, continuing the celebration of the Trinity and the gift of the Holy Spirit. This day maintains the festal character of the Pentecost season with special hymns and prayers. Many Orthodox communities hold additional services during Trinity Week to honor the complete revelation of the Triune God.

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 sacrament of reconciliation through which the faithful confess their sins to a priest and receive absolution. Also called the sacrament of repentance or penance, confession restores the baptismal purity lost through sin and reconciles the penitent with God and the Church. The penitent stands before an icon of Christ while confessing to the priest, who acts as a witness and minister of God's forgiveness. The priest then covers the penitent's head with his epitrachelion (stole) and pronounces the prayer of absolution.

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 sacrament of ordination to the threefold ministry of bishop, priest, or deacon. Ordinations take place during the Divine Liturgy, with deacons ordained after the consecration of the gifts, priests after the Great Entrance, and bishops after the Little Entrance. The bishop lays hands on the ordinand while the people sing "Axios!" ("He is worthy!"). Through ordination, the Holy Spirit grants the grace needed for ministry. Only men may be ordained, and bishops must be celibate monastics, while priests and deacons may be married before ordination.

The sacrament of healing for physical and spiritual ailments, administered by anointing with blessed oil. Also called the sacrament of anointing or Euchelaion, this service is traditionally celebrated by seven priests (though one may serve) who read seven Gospel passages and anoint the person seven times on the forehead, nostrils, cheeks, lips, chest, and hands. Holy Unction is offered not only to the dying but to all who are sick in body or soul, and many parishes celebrate it communally during Great Lent. The service emphasizes God's healing power and mercy.

The celebration of Christ's birth in Bethlehem. The feast is preceded by a 40-day Nativity Fast and celebrated with the Divine Liturgy, special hymns like the Troparion of the Nativity, and the blessing of homes.

The birth of St. John the Baptist, the Forerunner of Christ, to the elderly Zacharias and Elizabeth. Celebrated on June 24th, this feast honors the one who prepared the way for Christ's ministry. John's birth was miraculous, and he grew up in the desert to become the voice crying in the wilderness, baptizing Christ in the Jordan.

The joint commemoration of the two great apostles: Peter, the leader of the Twelve, and Paul, the Apostle to the Gentiles. Celebrated on June 29th after the Apostles' Fast, this feast honors both their ministries and their martyrdom in Rome. Though different in background, both were instrumental in establishing the early Church.

The brother physicians who provided free medical care and were martyred under Diocletian. Celebrated on November 1st, these 'Unmercenary Healers' treated both physical and spiritual ailments without accepting payment. They are patron saints of physicians and pharmacists. Their example shows how professional skills can be a form of Christian ministry and service.

The 20th-century Russian bishop who served Orthodox communities in China, Europe, and America. Celebrated on July 2nd, John (Maximovitch) was known for his ascetic life, care for orphans, and numerous miracles. He walked barefoot, rarely slept, and constantly prayed. He represents pastoral dedication and the universality of Orthodox faith across cultures.