Saint John Chrysostom (which means "Golden-Mouthed," after his eloquent speaking abilities) is one of the greatest preachers and theologians in Church history. His sermons and commentary on the scriptures are invaluable, and his bold preaching is held in the highest regard. Also a preeminent liturgist, his Divine Liturgy is still used in Orthodox churches worldwide.
He reposed on September 14, 407. As this is the Feast of the Cross, his feast is celebrated on November 13. He is also celebrated on January 27 and 30.