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 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 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.

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 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.