December 21 is the feast day Saint Thomas the Apostle, which we transfer to Monday if December 21 falls on a Sunday. We celebrate Saint Thomas two other times through the year: (1) on Dedication Sunday (always the first Sunday of October), in which we celebrate the dedication of our church and therefore Saint Thomas as its patron saint, and (2) on Low Sunday (the Second Sunday of Easter), when the resurrected Christ shows himself to the doubting Thomas.
To learn more about Saint Thomas the Apostle, consider these sermons in the archive.