“... I explain this impulse to the debate on the basis of the—in my view—clearest parallel between the Gospel of John and the Gospel of Thomas: the self-predication of Jesus as the light. This famous I-am word is found in John 8:12 as well as in Gos. Thom. 77a. Apart from this literal correspondence, both gospels and the Johannine Epistles contain light metaphors in a pronounced way (1 John 1:5–7; 2:7–11; John 1:4–10; 3:1–21; 9:4–5; 11:9–10; 12:35–36; 12:45–46; Gos. Thom. 11d, 24c, 33, 50, 61e, 83). What relevance does this phenomenon have for determining the relationship between the Johannine writings and the Gospel of Thomas? I have discussed this question in detail in a special essay. One central result of this investigation was that the christological and soteriological functions of the light metaphors are fundamentally different in both tradition circles. The Gospel of John has a christological focus of the light metaphors that is directed toward the audience acknowledging Jesus as the light of the world. Corresponding to this, the Gospel of John presents no anthropological motifs of an immanent light, the human capacity for knowledge (cf., e.g., Luke 11:33–36 par. Matt 6:22–23), and certainly no motifs of a saving spark of light in the disciples as they strive back toward their place of origin. This lack of such motifs is all the more striking as we recognize the Gospel of John’s pronounced language of immanence. Neither the language of immanence nor the light metaphors propagate the salvatory knowledge of an inner light, but instead the acknowledgment of Jesus as the light of the world. This shows a clear discrepancy to later early-gnostic and gnostic traditions, where the motif of a saving spark of light becomes a fundamental soteriological motif for the gnostics (Gos. Thom. 24c, 61e, 83). And such a fundamentally gnostic orientation can also be recognized in the light metaphors of the Gospel of Thomas. The light metaphors of the Gospel of Thomas are based on an anthropology that contradicts Johannine theology. ...”