The Internal Logic Of The Gospels
Contrary to the voice of critical scholarship for the last 200 years, I think we must re-assert that each of the four gospels stands on its own, and that each possesses its own internal logic. But what that logic is, is not always clear. Here is a possible solution.
In macro all four gospels begin with, or highlight early on, the Lord's baptism. Likewise each features at length his baptism into the death of the cross near the end. To me that is an obvious, and significant set of bookends.
Taking an even more macro view each gospel begins with the Lord's "rising up," (a la Deuteronomy 18:15) and ends with his rising from the dead. Matthew begins with his arising from the loins of Abraham, Mark has him rising up from his baptism now full of the Spirit, Luke has his arising from Adam, and in John he arises from God.
So these are possible larger thematics, while all that lies between leads the catechumen, worshiper, or inquirer from start to finish. In these intervening parts Jesus does two things. He teaches men about the Kingdom of God, and brings it about in real time by his miracles -- which further manifest the Kingdom, and allow men to participate in it.
To me this means that the gospels are unique. It means that it is impossible, and misleading in the extreme, to attempt to understand them by comparing them to another, already existing, forms of literature after which they are allegedly modeled. Instead, we should understand them to be inSpired Scripture in the same way that the Old Testament is Scripture.
As such, how are they to be employed? To me their three most obvious uses are as catechism, liturgy, and for missionary purposes. That is to say for the initiate, the worshiper, and the inquirer. To hear these is to hear the story of salvation with the implicit invitation to participate in it. To hear them is to hear the living voice of Jesus in the church in every age. To hear the blessed voice that forgives all of our sins, gives us good cheer, and invites us to the altar here in time, and there in eternity.