Saint Thomas is one of the twelve apostles of Jesus Christ in the Christian tradition. He is often referred to as "Doubting Thomas" because he initially doubted the resurrection of Jesus until he saw Him with his own eyes. His story is primarily found in the New Testament, particularly in the Gospel of John. After the resurrection, Saint Thomas is believed to have traveled to India to spread the teachings of Christianity. He is credited with establishing several Christian communities there. His feast day is celebrated on July 3rd in the Western Christian calendar and on December 21st in the Eastern Orthodox Church.