The Gospel of John differs so widely from the three Synoptic Gospels, both in its content and in its method of presenting Christ Jesus' career, that it is important to understand the reasons motivating John's individual treatment of the subject. In John, the Master's preaching appears to center in Judea; in the Synoptics, his basic work is done in Galilee. John says practically nothing of Jesus' parables, which stand in the forefront of the other accounts, and substitutes for them long discourses, such as those on the "true vine," "the bread of life," and the "good shepherd"; while in his Gospel no mention is made of such important events as the temptation, the transfiguration, and the ascension of the Master.
By the time John wrote, some twenty years after the latest of the other three evangelists, the Synoptic Gospels were well known, and widely read. Indeed, the early historian Eusebius informs us that John had studied them himself, and that, moreover, he "accepted them and bore witness to their truthfulness" (Ecclesiastical History: iii:24). What more natural than that he should supplement those earlier records, setting down chiefly what they had omitted? Further light is cast on the situation by John's own statement of his twofold purpose in writing his book, which was designed to establish faith in the Messiahship of Jesus and to inculcate the teaching of eternal life—"that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name" (John 20:31). The typical word used by John in describing Jesus' mighty works means literally "signs" (Authorized Version, "miracles"), and it is clear that he selected them as providing signs or proofs of his main thesis. For example, the Master's first sign at Cana "manifested forth his glory; and his disciples believed on him" (John 2:11). It is not surprising that John, who appears to have felt so strongly the fact of Jesus' Messiahship, should emphasize it from the very outset of his Gospel (see John 1:41; compare verses 34 and 49), while the Synoptic Gospel writers do not explicitly affirm it until the time of Peter's Messianic confession at Caesarea Philippi (Matthew 16:16): "Thou art the Christ, the Son of the living God."
Corresponding to John's deep realization of the transcendent authority of the great Teacher, whom he knew so well, we find in his Gospel a constant stress upon that authority. In Greek, the word "eimi" means "I am," but if special emphasis is desired, the word "ego" is added. This emphatic "I" is used by Jesus some one hundred and seventeen times in John's Gospel alone, as against some thirty-four times in the three Synoptic Gospels combined. In the earlier Gospels we find the Master commending the narrow way of life to his followers (Matthew 7:14); there he is hailed as a teacher of truth (Matthew 22:16), who gives the promise of eternal life (Mark 10:30); but it is John only who records Christ Jesus' words (John 14:6): "I am the way, the truth, and the life."
