Greg, helpful and provocative follow-up on RE: the Gospel.  I'm thankful for the piercing clarity you conclude with.  So good I'll copy them here just to be more closely associated with them:

You can see, therefore, why it's so jaw-droppingly ironic when people point to passages like that and say, "I'm going to preach the gospel like that!"  What they're so boldly and courageously declaring is, really, "I’m proudly going to preach the gospel as if I've never fully understood it!  I’m going to preach Jesus' Messiahship as an empty category, void of the content that Jesus himself poured into it through the course of his ministry!  I’m going to preach the gospel in ignorance!”

The four Gospels tell a story, and a significant theme in that story is how the disciples gradually came to understand what Jesus meant when he said, “The kingdom of God is at hand; therefore repent and believe.”  Every phrase of that tightly packed sentence was filled up with meaning as Jesus taught.  And through the course of the story, the disciples moved from ignorance to understanding.  Now, understanding that, I have to ask:  Why would anyone want to go to the part of the story where the disciples are still plainly ignorant and say, “Right there.  That’s my model for my preaching”? 

This is just entirely helpful, along with your exposition of how the developing understanding of the gospels and gospel should help us read briefer statements more fully.

A couple of reasons why someone would look at the disciples in their ignorance and say, "Right there, that's my model for preaching."

1.  Ignorance of our own.  How many have thought about the development of the gospels and the disciples' understanding as clearly as you state it here?  Statements about the disciples' ignorance and unbelief are clear enough in the gospels (John 2:22; 12:16; 14:26; Luke 24:5-8), but I don't knoww that we keep the original disciples' ignorance in mind as we read of their lives with the Lord.  So, an ignorance--benign in intent if not in effect--afflicts our reading of the Scripture, and subsequently our teaching of the Scripture.  And this basic ignorance gets compounded with a more serious ignorance of the Scriptures, of biblical, systematic and historical theology, and of the real needs of our people.  So we tend toward the adoption of messages consistent with our not knowing, our ignorance.

2.  Red letter Bibles and the authority of words.  This is a variation on the ignorance theme, but perhaps some people look to the words of Jesus and the words of the apostles in the gospels as somehow more authentic and paradigmatic.  We see this all the time in "scholarly" circles where critical analysis is king, and effort to get behind the text to the "real" words and meanings.  Red letter Bibles have become the layman's version of this same striving to get "behind" the words to the real or true words with authority.  I remember the first time I heard a Christian co-worker say to me when discussing something in Romans, "Yeah, but we're really just supposed to pay attention to the words in red.  Those are Jesus' words.  The rest don't count as much" or something like that.  That's one way you end up with "jaw-droppingly ironic" preaching methods and messages that leave a lot to be desired.  And among certain pastors, there is an attraction to "authenticity" and ancient forms.  In unsophisticated terms, that attraction tends toward  the simplistic (not simple).

3.  Laziness.  It doesn't require much to preach a gospel empty of the meaning that's placed into it by the whole of scripture.  It's easier to reduce it to an outline.  But to meditate on and preach the riches of the gospel in all their diamond-like light-refracting glory takes work.  How do you get to the gospel from 2 Samuel 18 without tacking on a little outline or plea at the end?  Work.  Application of the whole counsel of God.  Biblical theology.  Systematic theology.  Careful exegesis.  Work.

4.  Trendiness.  Not everyone who takes the approach we lament is lazy or ignorant.  Some are trendy.  It's trendy right now to speak as though this or that camp i ssomehow the theological and methodological descendants of the original apostles and practicing just as they did.  Church buildings are out.  Candles are in.  Done with any liturgy or structure; let's get on with community ambiguously construed.  Reading our NTs or church history for "what the early church did" is fashionable.  Now, that examination has its place and is necessary to our understanding.  But, there exists a kind of "really old is kool" trendiness and shallowness about some of this.  A disdain or indifference toward the contemporary church prompts an odd anti-church reading of the Scripture, and all of that is labeled en vogue, cool, trendy, and a host of other phrases.

5.  Social concern.  A lot of social justice concern is poured into the broader definitions of the gospel and the way it's preached.  The formulation you insist on at bottom, seems to disallow such concerns.  Some think insistence on personal repentance and faith, sin and wrath, and forgiveness and eternal life creates an other-worldly perspective that weakens this-worldly mission.  And to be fair, for too many preachers and Christians this biblical definition and essential message has at least limited social concern to this or that favorite issue, if not removed it altogether.  So the broader kingdom emphasis, with simplicity and ambiguity as handmaidens, opens for some a door for ensuring these important things are included. 

6.  Fear of man.  One can't help but think that some of this attempt to redefine the gospel in terms that downplay substitution, sin, wrath, and the call to repentance and faith finds its impetus in the fear of man.  Let's face it: preaching the gospel has always been and will always be wildly unpopular with sinners and with many professing Christians who love the Lord but who've never thought long about such issues.  If the preacher's soul tires of staring into unhappy and indifferent faces, cowers at offending, or finds resistance to the gospel discouraging, he'll not be long in preaching the gospel with application to individuals.  He'll find "the kingdom" or something called "the gospel" with no personal demands safer ground for his feet.  And he'll stand there rather than outside the camp, at the flaming hot gates of hell, where there is opposition, persecution, slander, reviling, and suffering.