John’s gospel begins with e Word," who "became flesh" (John 1:1, 14). John concludes his treatise with the Lord’s blessing on those who believe His words, rather than, like Thomas, depending on sight (John 20:29). Faith in the written Word is the purpose (20:31) and theme of John’s gospel. The miracles developed the disciples’ faith (John 2:11; John 20:30); all were through His word. The Lord taught His own that His words afforded them the same sufficiency as His person.
In 18:9, John notes the fulfilling of the Lord’s sayings with the same expression He uses regarding the fulfilling of Scripture (John 12:38; 15:25). The incarnate Word and the written Word are equally authoritative; their sayings both must be fulfilled.
Only John tells us the Lord is "the true Bread"(6:32), the Bread of which manna was typical. Manna, then, typifies the Incarnate and the written Word (Deuteronomy 8:3). The written Word is as life-sustaining, sufficient, and authoritative to us as the Incarnate Word was to the disciples.