In a phrase now famous, Clement of Alexandria (ca. a.d. 150-215) referred to the Fourth Gospel as “the spiritual gospel.” This he set in distinction to the other gospels, which had recorded, he felt, the “bodily facts” of Jesus' life and ministry. Since his day, we have come to understand that the Synoptic writers were also theologians with spiritual agendas, even where they seem most factual. Nevertheless, the Fourth Gospel has a distinctive style that shows it to be without question the result of profound theological reflection.
To see this, one need look no further than its use of language. It is not written in excellent Greek, at least not by classical standards; neither is its Greek poor, to judge from the remains of nonliterary writing of the first century. Even in English translation, the style is straightforward and the vocabulary fairly simple. But this in itself presents the reader with a challenge. For, although the text may seem plain and easy to comprehend, it repeatedly rises to heights of thought and spiritual insight that test even the most adept. Perhaps the prime example is the prologue (1:1-18), which introduces many of the themes to be developed later in the book. The modern reader does need some explanation of the name Word, it is true. But, apart from that, everything else seems at first sight readily accessible. Yet these verses address some very weighty topics: for example, Christ's preexistence and incarnation and the believer's life and salvation. The author did not come to comprehend such things in an instant; neither will his audience.
In addition, everything in John's gospel, even when Jesus speaks, is presented more or less uniformly in the idiom of the author. For this reason, it is not always possible to tell where a character leaves off speaking and the author begins. It is debated, for instance, whether Jesus' words to Nicodemus end with 3:21 or some verses earlier or whether the testimony of John the Baptist ends with 3:36 or with the climactic words of 3:30. In both cases, ending the speech earlier requires one to understand that the author has added a paragraph of interpretation to the account. But there is insufficient distinction between the speeches of the characters and John's regular manner of expression to be certain. His own language has colored everything; everything has passed through his thinking and received his impress.
The author's theological interests are readily apparent. Even quite ordinary, everyday things become symbols of spiritual realities beyond physical sight. Bread becomes a symbol of the spiritual food given by God in Jesus, who is the “bread of life” (6:35-58), and water the symbol of the Spirit (7:37-39), who was to be given to believers when Jesus had been glorified. This spiritual dimension, always present when Jesus speaks, is made prominent by a feature found frequently in his conversations. He will make an assertion that can be taken in more than one way. Although it rapidly becomes clear that for him the words carry a spiritual meaning, what he has said is misunderstood because it is viewed in a purely earthly way. This leads to a further statement, which clarifies the issue. Thus, for example, the conversation with Nicodemus turns on a Greek word that may mean either spiritually “from above” (Jesus' meaning) or simply “again” (Nicodemus's understanding) (3:3-8). Jesus is similarly misunderstood when he speaks to the woman of Sychar about “living water” (4:7-15) and when he tells the Jews about his impending return to the Father (7:33-36).