The Feast of St. Paul is celebrated on January 25 each year, marking the conversion of St. Paul the Apostle. This day honors his significant role in spreading Christianity and his contributions to the New Testament. The feast is observed by various Christian denominations, including the Roman Catholic Church and the Eastern Orthodox Church. It often includes special church services, prayers, and reflections on St. Paul's teachings and missionary journeys, emphasizing his transformation from a persecutor of Christians to one of their most ardent advocates.