Chilton, Bruce. "Chapter Six: The Gospel According to Thomas as a Source of Jesus' Teaching." in Wenham, David (editor), The Jesus Tradition Outside the Gospels. Sheffield: JSOT Press, 1984, 155-175.
"The Gospel According to Thomas consists of some 114 sayings of Jesus, and has no narrative element which can compare with what we find in the canonical Gospels" (Wenham [editor] 1984, 155). There is a valid question as to whether the sayings are actually Jesus' teaching. Chilton observes that the codices containing Thomas are from the fourth century and that some fragmentary parts may be dated to the third century. However, Chilton does consider it within the realm of possibility hat the tradition represents material as old as that in the canonical Gospels. Helmut Koester is a proponent of a view that Thomas is identified as the twin of Jesus and speaks in much the same way, reporting Jesus' statements accurately (Wenham [editor] 1984, 156).
Chilton evaluates some of the syaings attributed to Jesus in Thomas, noting that similar ideas may appear in the New Testament, but that some are contrary in spirit to the message of the New Testament (Wenham [editor] 1984, 157). He concludes that Thomas is not really comparable to Q, assuming Q is a source of the Synoptic Gospels (Wenham [editor] 1984, 159).
Chilton observes that there is a relationship between Thomas nd the Diatessaron, which Quispel considers to stem from mutual dependence on "a tradition he calls 'the Gospel of the Hebrews'" (Wenham [editor] 1984, 159). A substantial difficulty with this view is the fact that Tatian's Diatessaron is not available to us, though some harmonies of it do exist. Chilton further notes that Thomas is really a work of the second century, though it shows some signs of contact with earlier sources (Wenham [editor] 1984, 160). The work reached its current form some time in the fourth century. The structure of Thomas is a series of questions from an interlocutor, answered by sayings of Jesus. This creats a topical collection of sayings (Wenham [editor] 1984, 161).
Chilton considers the reliability of Thomas (Wenham [editor] 1984, 162). This is a challenging issue. The work has a central focus on God's kingdom, as does Matthew. Thomas is easily and often understood as showing a great deal of Gnostic ualism. However, Chilton asserts, "It is no more hterodox, say, than Clement of Alexandria, and is far removed from the elaborate cosmology of The Gospel of Truth" (Wenham [editor] 1984, 163). There is, therefore, some credible reason to consider the work relatively orthodox. The text largely posits an internal kingdom as opposed to one extra nos, but this emphasis can be found throughout the canonical Scripture as well (Wenham [editor] 1984, 164). Chilton also understands the references to "the kingdom" to be a taboo deformation, as they serve as references to God. He illusrates this idea at length.
Chilton concludes that while Thomas has some sayings which seem to be genuinely sayings of Jesus, other parts are inconsistent. The ideas sometimes tend toward those of the Gnostics. "In practice, Thomas can only be trusted as a witness to the sayings of Jesus to a limited extent," he concludes (Wenham [editor] 1984, 171). He advocates careful historical judgment and a sound grasp of tradition to guard our interpretation.