In the Synoptic Gospels and Acts, Thomas is mentioned only in the four lists of the Apostles (Mk 3:18; Mt 10:3; Lk 6:15; Ac 1:13). Appearing about midway through these lists, he seems to have been regarded as relatively unimportant among the Twelve. By contrast, in John’s Gospel, Thomas is presented as a central character, featuring prominently in four major scenes. In three of those scenes Thomas is given the additional name Didymus (Twin), a name exclusive to him in John’s Gospel and later tradition, especially in connection with Syrian Edessa. By the 4th century, Edessa had become famous for its special veneration of the Apostle Thomas, with sources featuring Thomas as the missionary link between Jesus and the early Christianisation of lands from Syria to India. The Edessan School of Thomas developed an encratic school of devotion to Thomas as the mystical twin of Jesus and prototypical Christian healer, and the Syrian city housed an established shrine for his remains. Scholars rightly contest the historical value of these sources, but analysis of their provenance, content and reception allows us to outline a picture whose lines converge in a coherent and plausible tradition of devotion that, in just a few centuries, reached as far east as India and as far west as Spain, Gaul, and Britain.

The Synoptics narrate a single Passover during Jesus’ ministry, whereas John's Gospel spans three Passovers. The Diatessaron harmonised the Four Gospels, but previous scholarship has misapprehended Tatian's chronology of Jesus’ ministry. The Diatessaron included all the Johannine festivals, but Tatian rearranged the order of events. Distinctively resolving a significant disagreement between John and the Synoptics, Tatian innovated a narrative sequence wherein Jesus’ temple disruption occurs at the second of three Passovers.

While the vast majority of manuscripts portray Jesus in Mark 1.41 as ‘moved to compassion’ (σπλαγχνισθείς) before healing a leper, five putative witnesses in three languages depict him ‘becoming angry’ (ὀργισθείς/iratus). Following Hort's dictum that ‘knowledge of documents should precede final judgments on readings’, this article offers the first thorough examination of the witnesses to ‘anger’, with the result that the sole putative Syriac witness is dismissed, the Old Latin witnesses are geographically isolated, and the sole Greek witness linked to the Old Latin as a Greek–Latin diglot. Since the final grounds for Jesus’ ‘anger’, that it is the lectio difficilior, also prove insubstantial, σπλαγχνισθείς is concluded to be original, with ‘anger’ originating in the Old Latin manuscript tradition.