St. Gregory Palamas (1296-1359)

Archbishop of Thessalonica, the great defender of Hesychasm and the theology of the uncreated divine light. Articulated the essence-energies distinction: God's essence is unknowable, but His uncreated energies (grace, light) are participable. Vindicated at the Councils of 1341 and 1351. His theology is central to Orthodox spirituality. Feast: November 14; Second Sunday of Great Lent.