The 14th-century Archbishop of Thessalonica who defended hesychast spirituality and taught about the uncreated energies of God. Celebrated on the Second Sunday of Lent, Palamas developed theological foundations for mystical prayer and the Jesus Prayer tradition. His teachings on theosis (deification) are central to Orthodox spiritual life.

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 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.