Didymus is the Greek word meaning 'twin' and serves as the Greek equivalent of the Aramaic name Thomas (Toma). It is used in John's Gospel to identify the apostle Thomas as 'the Twin.' The name is purely descriptive of his birth circumstance, but Thomas himself became one of the most theologically revealing disciples in John's Gospel.
Thomas is often unfairly reduced to 'Doubting Thomas,' but John's portrayal is far more nuanced and profound. His doubt is not cynical unbelief but the anguished wrestling of a man who deeply wants it to be true. When Jesus appears and Thomas sees and believes, his confession — 'My Lord and my God!' — is the highest Christological declaration in the Synoptic tradition. Jesus's response honors Thomas while pointing beyond him: 'Blessed are those who have not seen and yet have believed.'