Why is the Gospel of John so different from the other gospels? Is there a different motivation or historical circumstances?
The Gospel of John is very different from the other three. The three (Matthew, Mark, and Luke) are called the Synoptic gospels because they take one basic point of view of Jesus' lifem teachings, and the like. There are certainly differences among them, but nothing like the difference from John, as you suggest. John seems to have grown through a different tradition about Jesus. It is probably a combination of motivation (the personal interest and theological commitments of the evangelist) and audience that makes this gospel so different. If you were asked to tell the story of Jesus to, say, a Jewish youth group, a bunch of philosophy majors in college, or a group of senior citizens who had long been in the church, you would instantly recognize the different concerns of each group (whether rightly or wrongly!) and use vocabulary and discuss concepts appropriate and persuasive for each. That raises the question of John's audience in a big way. We do not know.
There are many theories. I suggest Luke Timothy Johnson's, The Writings of the New Testament. It has very good introductory material on all the gospels, as well as other Johannine writings.
You are correct to discern the marked difference between John and the other three Gospels, Matthew, Mark and Luke. These three have the same basic outline of an one-year ministry for Jesus who, after his baptism by John, begins preaching and healing in Galilee, gathers disciples, and then by the following spring comes to Judea and Jerusalem for the confrontation with the religious authorities and his death and resurrection. The first three Gospels are called "Synoptics" by scholars from a Greek word "to see together" because of their close similarities which fact quite likely is due to the fact that Matthew and Luke knew the Gospel of Mark and incorporated it into theirs. But the Gospel of John is very different, featuring three trips to Jerusalem (and thus presumably a 2 1/2 year ministry) and quite distinct vocabulary contrasting belief and unbelief, light and darkness, truth and falsehood. No one knows with certainty who the author was, or under what circumstances he wrote, or whether he knew any of the other Gospels, or why he wrote as he wrote. However, a wide consensus of scholars holds that the Gospel is a magnificent work in literary form and theological depth, exploring the mystery of deity in Jesus and the personal union of believers with him, and thus its unknown author was a brilliant thinker and writer. The ancient Church fathers called the Gospel of John the "spiritual" Gospel for that reason. The tradition developed that it was written by John the apostle and son of Zebedee, and that, because he knew allegedly the other Gospels, he decided to write a different one. This tradition may contain some truth in it at least to the extent that the author quite likely was a Jewish Christian who learned Greek very well and had a profound sense of personal fellowship with the risen Jesus. Another ancient tradition holds that at the city of Ephesus, where presumably this Gospel took shape, there were two famous Johns, one the apostle and another John the Elder, who may have been the actual author of the Gospel. No matter who the author, the Gospel of John is a masterpiece of literature and theology. A troubling shortcoming is that it generalizes and impugns "the Jews" as sons of the devil and killers of the Son of God. This shortcoming is moderated by the fact that such polemic in John is viewed as "intra-Jewish" or polemic between Jews themselves over religious questions, known in those days from other sources (Essene or Qumran documents against fellow Jews as "sons of darkness"). Nevertheless, Christians reading the Gospel ought to be extremely concerned not to accept this polemic at face value and turn it against the Jewish people whom God loves as His people and as much as any other people--all being His creation and deserving of His love and care. In other words, the Gospel of John in its own context is not necessarily "anti-Jewish" (having to do with religion), and much less "anti-Semitic" (having to do with race), but it can wrongly be used that way and tragically has been used that way in history by Christians who thus betrayed the Lord's commandment of love towards all.
The other three Gospels are called "Synoptic" Gospels, because they worked together with a "common view", which is what synoptic means. John worked separately with a different experience of Jesus. Versus a mighty Gnostic movement, which had trouble with Jesus' earthly, fleshly presence of the divine, John emphasized the reality of the divine revealer in human experience: God becoming human to redeem us.
The distinctive nature of the Gospel of John has been a source of puzzlement and inquiry for a long time, and (as so often is the case) the discussion has been complex. But, to cut to the heart of the matter, many scholars think that the Gospel of John originated among a particular group of early Christians, for whom "the disciple whom Jesus loved" (referred to in 13:23; 19:26; 21:7, 20-25) may have been the key figure whose teaching and testimony about Jesus was deemed particularly valuable. Our present Gospel of John may have been edited after the death of this figure (alluded to in 21:22-23).
The distinctive order and selection of material in John seems to reflect the distinguishing emphases. So, for example, Jesus' movements and actions are linked at various points with Jewish feasts. Also, the author refers to Jesus' miracles as "signs", and there seem to be seven of them, culminating in the raising of Lazarus.
But perhaps the most striking feature is the very explicit way that Jesus speaks of his own significance in John, using terms and declarations that seem obviously to reflect the preaching and claims of the early believers generated by Jesus' resurrection. The reason for this is probably given in John 14--16, where Jesus is pictured as repeatedly referring to the future revealing and teaching work of the Holy Spirit (referred to distinctively as "the Counsellor" or "Advocate"). In short, the Gospel of John seems to be an account of the earthly ministry of Jesus portrayed quite deliberately through the greater insight into his significance that came after his death and the experience of his resurrection among early Christians.
Dave asks: “Why is the Gospel of John so different from the other gospels? Is there a different motivation or historical circumstance?”
The short answer is, Both. The historical situation of the congregation for which the gospel was written was different from that of the first three gospels, and so consequently was the writer’s motivation in writing for the pastoral needs of this particular congregation.
The first three gospels were written probably during and after the Jewish-Roman War of A.D. 66-70, and for the purpose of preserving as much as possible of the actual words and deeds of Jesus’ ministry, by writing them down before those who remembered them might forget them, or be lost, or die. Thus we have a “first draft” in the gospel of Mark, and two similar but different expansions in the gospels of Matthew and Luke.
“John” is a different story. The congregation for which it was written lived at the end of the century; the Jewish community had definitively “de-synagogued” (viz. “excommunicated”: John 9:22; 12:42; 16:2) the Christians; the Johannine congregation had the first three gospels, but felt they needed more, viz. a gospel which would speak to their own specific, present pastoral needs. They said, as it were, “We know what Jesus said and did, and what happened to him, 70 years ago. But what does Jesus Christ mean for us now, today?”
And so the author, writing under the name of the “disciple whom Jesus loved,” composed his gospel in order to speak to this burning question of his congregation. He took certain stories about the ministry of Jesus, and retold those stories in a way which would speak directly to the needs of his congregation. The result was something like a “double exposure” (to which film in old cameras was sometimes subject). The “first exposure,” as it were, was a picture of Jesus as he spoke, acted and suffered during his actual ministry around the year A.D. 30. But the “second exposure,” as it were, showed to the Johannine congregation what those words, acts, and suffering of Jesus meant to that congregation in its actual, uncertain, threatened life and existence at the end of the first century A.D., now some 70 years after the ministry of Jesus. For them, that is to say, Jesus was not just someone who preached, suffered and died a long time ago; rather, he was the risen Jesus as the Christ who was present and active for them, in their own life, as the Holy Spirit, the “Paraclete” or Comforter.
That is what the Gospel of John was meant to do for them. And that is what we hope it may do for us today as well.
Thousands of pages have been filled with enlightening answers to this very question. All of these are recorded in well crafted books and essays, so my answer here is not going to reveal anything new on the subject. But I hope that it will still be helpful to you.
You noticed correctly that John is different. As I say in my classes, John is a different “animal.” It is actually a bird, an eagle, according to the traditional symbols associated with them (Luke is the Ox, Matthew is the Man, and Mark is the Lion). As an eagle, John rises above the horizon and flies high in the sky from which it drops unexpectedly to center on its prey, Jesus the Word of God, Jesus the pre-existent Son of God. John’s movements are swift and determinate. There is not a hint of doubt or ambiguity. Jesus is divine from the very beginning.
Why is that so? What is the motivation, as you put it, behind such a description? Well, John’s motivation is not different from the other evangelists. He is trying to make an apology, a convincing apology for his view of who Jesus was –and still is- for his community. The apology was necessary because the public perception about who Jesus was had been influenced by the way Jesus died: executed by the Romans. How do you change such a negative connotation, namely, that the leader of your movement was an outlaw who deserved, in the eyes of the Empire, death by crucifixion? Well, you make an as exalted as possible apology, a defense of who your leader really was, because in so doing you are making an apology of who you are. You are actually defending yourself, and your group, against external accusations.
The historical circumstances for the writing of John may have been the situation in Palestine that developed after the destruction of the Jewish Temple in 70 CE by the Romans. This catastrophic event brought the Jewish communities into a deep theological crisis not too different from the one produced by the Babylonian exile in the 6th. Century BCE. They tried to make sense of the situation by asking themselves such questions as: How is it possible that the temple, the site of God’s indwelling, has been destroyed by a foreign, idolatrous power? What does that say about God and, conversely, what does that say about us? Is God still with us? And if so, how do we know it? Some Jewish communities answered this dilemma by turning to the study of the Law and to prayer as activities that came to replace the now-forever- gone temple and its sacrificial system. Others turned to an event that had changed their lives: the words, deeds, and death of Jesus of Nazareth, who they believed to be the Jewish Messiah, the pre-existent Son of God. This belief came also to replace, for some Jewish people, the temple system.
Both communities challenged each other in terms of who was right and who was wrong and this debate is recorded in the gospel of John, albeit there we only hear the Johannine community’s voice. The differences with the other gospels reside on the fact that the community that produced the Gospel of John, because of its specific historical circumstances, used a set of traditions that best served their apologetic purpose. Content was determined by context. Because the context for the other gospels was somehow different they give us a picture of Jesus that is also different, although all of them share the same post-destruction of the temple historical situation.