Introduction: The Relationship of John's Gospel to the Synoptics.
Two basic positions on the relationship of John’s Gospel to the Synoptics are possible:

If John knew of the synoptics, then he wrote to supplement them. (To say John knew of one or more of the synoptics is not to say, however, that he wrote his gospel with copies of Matthew, Mark, and/or Luke in front of him. John may have been aware of the existence of other written accounts of Jesus’ life and ministry without actually having seen them.)
If John’s Gospel is totally independent from the synoptics, he had enough material to choose from that much of it does not overlap with the synoptics (cf. Jn 20:30 and 21:25). This point is strengthened considerably if one accepts the Fourth Gospel’s claim to reflect eyewitness testimony about the life and ministry of Jesus (John 21:23-24).
Major Differences:
1. Omission by John of material found in the synoptics.
John’s Gospel omits a large amount of material found in the synoptic Gospels, including some surprisingly important episodes: the temptation of Jesus, Jesus’ transfiguration, and the institution of the Lord’s supper are not mentioned by John. John mentions no examples of Jesus casting out demons. The sermon on the mount and the Lord’s prayer are not found in the Fourth Gospel. There are no narrative parables in John’s Gospel (most scholars do not regard John 15:1-8 [“the Vine and the Branches”] as a parable in the strict sense).

2. Inclusion by John of material not found in the synoptics.
John also includes a considerable amount of material not found in the synoptics. All the material in John 2—4, Jesus’ early Galilean ministry, is not found in the synoptics. Prior visits of Jesus to Jerusalem before the passion week are mentioned in John but not found in the synoptics. The seventh sign-mira