The idea that the gospel is primarily news of victory won by Jesus, not advice for more moral living, is a very liberating thought. I came across a good explanation of this in D. Martyn Lloyd-Jones’ collection of sermons on Isaiah 40, The All-Sufficient God:
The gospel is not an exhortation, nor is it an appeal. It is not the announcement of some kind of new programme or some wonderful new idea that someone has thought out and that you and I must put into practice. No, no, that would not be comfort, would it? I have never found it particularly comforting to be confronted by the Ten Commandments and the Sermon on the Mount. In and of itself, there is not much comfort in being told, ‘Be ye therefore perfect’ (Matt. 5:48). But the gospel does not tell us things like that until it has first told us something else. And that something else is the great good news…The gospel is the announcement, the proclamation, of the greatest and the most astonishing good news that has ever come into the world of time.
Don’t think of the Christian faith as a self-improvement program that you take on, but as a liberation rescue mission that God has taken on.
Second Mile Church Blog 
#1 by Kevin on July 3, 2008 - 10:28 am
From Jonathon Edwards ‘The Religious Affections’
Truly to see the truth of the word of God, is to see the truth of the gospel; which is the glorious doctrine the word of God contains, concerning God, and Jesus Christ, and the way of salvation by him, and the world of glory that he is entered into, and purchased for all them who believe; and not a revelation that such and such particular persons are true Christians, and shall go to heave