The goal of these study guides is to provide insight into the possible applications of the material found in the synoptic gospels, although they do not comprehensively cover every verse in the gospels. I am covering the synoptic gospels separate from John as they cover common material and have a common emphasis separate to a degree from John. In particular my impression is that the synoptics focus on Lordship of Christ and quality of faith issues, whereas John focusses on Christ as Savior and the object of faith issues. The synoptics give the impression of being a bit more "Jewish" in emphasis, speaking of Jesus as the Messiah and Son of David. John gives a more global impression speaking of Jesus as the Son of God and Savior of the world. In fact the word "world" is used only 22 times (NIV) in all the synoptics taken together - and much of that is redundant. Whereas it is used 57 times (NIV) in the gospel of John alone.
Of course both sets of gospels are true and applicable. There are ultradispensationalists who would throw away the synoptics (and some even the gospel of John), claiming them only applicable to Jews at the time. I don't think that was John's intention in writing his gospel. I perceive that he expected Christians to continue to read and apply the synoptics. But his intention in writing John was to incorporated other material not covered in the synoptics that would be appropriate for Gentiles as the gospel was moving westward.
Application: The order that the books are found in the New Testament is perhaps the best way to study them. The synoptics clarify the Jewish roots of the faith and like the Jews wandering in the desert before entering the promise land, they deal with material appropriate to prepare one to understand the gospel of John and the letters.
