The Acts of Thomas are considered to be the cornerstone Gnostic writings (Therefore finally rejected as heretical by the church at the Council of Trent.) Arguably Thomas is the most Gnostic of the apocryphal Acts, portraying Christ as the "Heavenly Redeemer", independent of and beyond creation, who can free souls from the darkness of the world.

The Acts of Thomas are the only Acts that claim self-authorship. Thought to have been written in the 200s C.E., though the Gospel of Thomas places it earlier.

The Acts of Thomas is the story of Thomas' evangelical mission to India. He is not martyred, instead he dies in prison, but not before sings the "Hymn of the Pearl," a poem that gained a great deal of popularity in orthodox circles. (The hymn itself is shrouded in mystery: is it parable or prophesy?) He was imprisoned while converting Indian followers won via performing miracles because he'd earned the ire of the monarch Misdaeus because of his conversion of Misdaeus' wives and a relative Charisius.

Thomas was the younger brother of Jesus. He himself and his church, surviving for a little while after his death, was often seen in conflict with Peter's church. Thomas often referred to Peter as "the liar". There are some Gnostic texts (not The Acts of Thomas) that suggest the Jesus was taken from the cross alive, other Gnostic texts suggest the Jesus and Mary Magdalene were married and had two sons and that Jesus and Mary were equal partners in the early church, that Mary and her sons were hidden after Jesus' crucifixion, etc.