It concerns the end of the world, and appears to be influenced by the Apocalypse of John (better known later as the Book of Revelation), although it is written in a less mystical and cosmic manner.
From roughly 1600–1900, the Apocalypse of Thomas was only known to exist by hostile references to it in the sixth century Gelasian Decree, which condemned the work as apocrypha not to be read.
[2] Aurelio de Santos Otero [es] writes that the author appears to be familiar with, or at least was influenced by, various other apocalyptic literature other than the Apocalypse of John, including the Assumption of Moses, the Ascension of Isaiah, and the Sibylline Oracles.
[1] The Apocalypse of Thomas was widespread in Northwestern Europe, with manuscripts dating between the eighth and the eleventh century.
Despite the condemnation in the Gelasian Decree,[3] this did not seem to curtail its popularity: the Apocalypse was most likely accepted as canonical "in certain parts of Western Christendom in the ninth and tenth centuries".