Thomas, also called St. Thomas, Judas Thomas or Didymus, was one of the twelve apostles of Jesus. The Synoptic Gospels and Acts list this "twin" (Toma means twin in Aramaic, as does Didymus in Greek) among the apostles (Mt 10:3, Mk 3:18, Lk 6:15).
Thomas appears in a few passages in the Gospel of John. In John 11:16, when Lazarus has just died, the disciples are resisting Jesus' decision to return to Judea, where the Jews had previously tried to stone Jesus. Jesus is determined, but Thomas has the last word: "Let us also go, that we might die with him" (NIV). Some interpret this to anticipate St. Paul's theological conception of "dying with Christ".
He also speaks up at The Last Supper in John 14:5. Jesus assures his disciples that they know where he is going, but Thomas protests that they don't know at all. Jesus replies to this and to Philip's requests with a detailed and difficult exposition of his relationship to God the Father.