The missionary journeys of Thomas — a disciple of Jesus Christ — were ones of surprising and confronting encounters. Thomas was an early Christian who knew that life could change — which can move a person on to more superhuman endeavours and accomplishments. According to historical tradition, Thomas travelled to the Parthian Empire, and India. In this article, the evidence for these historical traditions is presented together for the first time. By bringing together an array of ancient sources, including literary, archaeological, numismatic and epigraphic evidence, this article demonstrates that Thomas’s journeys to the East contained elements of religious experience, continuity and change, set in their historical contexts. Thus, in this article the missionary exploits of Thomas are explored, as are factors of the worlds and contexts he lived and moved in, which highlight the importance of Thomas and his exploits in his own times.