Elizabeth Harris demonstrates that a type of prologue found in ancient Greek literature could be the literary convention behind John 1:1–18. The structure and content of the Johannine prologue determine the structure and content of the whole Gospel. It provides the reader with seminal statements about the cosmic situation and God’s plan for mankind, statements which are explicated thereafter. This function of the prologue is explored through the three historical personages mentioned in that largely metaphysical construction about the Logos: John, Moses and Jesus Christ. The person and mission of Jesus Christ, cryptically stated in the prologue, are explicated through three Christological expressions: “the Son of Man,” “I am,” and “the Son (of God).” These require the Logos-creator conception in the background to give them theological coherence.