 
Preach ChristÂ
For I delivered to you as of first importance what I also received: that Christ died for our sins in accordance with the Scriptures, that he was buried, that he was raised on the third day in accordance with the Scriptures. . . .
1 Cor. 15:3-4
The gospel is the good news that God in Christ has come into the world and by his life, death, burial, and resurrection has conquered our greatest enemies: the world, the flesh, sin, death, and the devil. The gospel is the proclamation that our sins are forgiven and we are under condemnation no more. This gospel calls forth a response of faith and repentance where upon we receive Christ’s righteousness and are granted right standing in the Father’s sight. Our response allows the Holy Spirit to transform our entire beings making us new creations in Christ.
Of all I would wish to say this is the sum; my brethren, preach Christ, always and evermore. He is the whole gospel. His person, offices, and work must be our one great, all-comprehending theme.
The world needs to be told of its Saviour, and of the way to reach him. Justification by faith should be far more than it is the daily testimony of Protestant pulpits; and if with this master-truth there should be more generally associated the other great doctrines of grace, the better for our church and our age. . .
We are not called to proclaim philosophy and metaphysics, but the simple gospel. Man’s fall, his need of a new birth, forgiveness through an atonement, and salvation as the result of faith, these are our battle-axe and weapons of war.
We have enough to do to learn and teach these great truths, and accursed be that learning which shall divert us from our mission, or that wilful ignorance which shall cripple us in its pursuit.
Charles H. Spurgeon, Lectures to My Students, 1875-94Â (Carlisle, PA: Banner of Truth Trust, 2008), 87-88, paragraphing mine.
HT: Desiring God