Saint Thomas, one of the Twelve Apostles, called Didymus. According to John, he refused to believe in the resurrection until he saw Jesus' wounds; hence the expression
John 11.16; 14.5; 20.24–29; 21.2. By tradition he is said to have gone as missionary to Parthia or India. The Syriac-rite Christians of Malabar, India, whose church was established by the 3d cent., claim St. Thomas as their founder. Among the Pseudepigrapha are a Gospel of Thomas and Acts of Thomas. In addition, a Gospel of Thomas was among the 4th-century Coptic books found at Nag Hammadi. Feast: Dec. 21.
See E. Pagels, Beyond Belief: The Secret Gospel of Thomas (2003).