“Thomas” in Hebrew or Aramaic means “twin”.
He is known as “Doubting Thomas” because he refused to believe that Christ had indeed risen until he had seen for himself, but when he had seen Him, Thomas said to the Risen Jesus, “My Lord and My God.” (John 20:19-29)
However, Saint Thomas, when Jesus announced his intentions of going to Jerusalem in spite of the dangers to his life there, said to the others, “Let us also go, that we may die with him.” (John 11:7,8,16) If Thomas was pessimistic, he was also sturdily loyal.
Saint Thomas is mentioned again (John 21) as one of the seven disciples who were fishing on the Sea of Galilee when the Risen Lord appeared to them.
Aside from this he appears in the New Testament only as a name on lists of Apostles.
A couple of centuries later a story has it that Saint Thomas had gone to preach in India. The tradition among Christians in India is that Saint Thomas was speared to death near Madras, and accordingly a spear is his symbol.
His Feast Day is celebrated on July 3.