The Gospel is the good news about the great salvation purchased by Jesus Christ, by which He reconciled sinful men to a holy God.
The good news of the Gospel is that Jesus lived a life of perfect righteousness, of perfect obedience to God, not for His own well being but for His people. He has done for me what I couldn’t possibly do for myself. But not only has He lived that life of perfect obedience, He offered Himself as a perfect sacrifice to satisfy the justice and the righteousness of God.
The gospel of Christ in general is this: It is the good tidings that God has revealed concerning Christ. More largely it is this: As all mankind was lost in Adam and became the children of wrath, put under the sentence of death, God, though He left His fallen angels and has reserved them in the chains of eternal darkness, yet He has thought upon the children of men and has provided a way of atonement to reconcile them to Himself again...Namely, the second person of the Trinity takes man's nature upon Himself, and becomes the Head of a second covenant, standing charged with sin. He answers for it by suffering what the law and divine justice required, and by making satisfaction by keeping the law perfectly, which satisfaction and righteousness He tenders up to the Father as a sweet savor of rest for the souls that are given to Him...And now this mediation of Christ is, by the appointment of the Father, preached to the children of men, of whatever nation or rank, freely offering this atonement unto sinners for atonement, requiring them to believe in Him and, upon believing, promising not only a discharge of all their former sins, but that they shall not enter into condemnation, that none of their sins or unworthiness shall ever hinder the peace of God with them, but that they shall through Him be received into the number of those who shall have the image of God again to be renewed unto them, and they they shall be kept by the power of God through faith unto salvation.
...and Heaven have mercy on us all - Presbyterians and Pagans alike - for we are all dreadfully cracked about the head and desperately in need of mending.
Herman Melville in "Moby Dick"
We must not suppose that if we succeeded in making everyone nice we should have saved their souls. A world of nice people, content in their own niceness, looking no further, turned away from God, would be just as desperately in need of salvation as a miserable world.
We must have the full message. . . 'deliver the whole counsel of God'. . . . It starts with the Law. The Law of God ... the demands of a righteous God, the wrath of God. That is the way to bring men and women to conviction; not by modifying the Truth.... We must confront them with the fact that they are men and that they are fallible men, that they are dying men, that they are sinful men, and that they will all have to stand before God at the Bar of Eternal Judgement....And then we must present to them the full-orbed doctrine of the Grace of God in Salvation in Jesus Christ. We must show that no man is saved 'by the deeds of the Law', by his own goodness or righteousness, or church membership or anything else, but solely, utterly, entirely by the free gift of God in Jesus Christ His Son. . . . We must preach the full-orbed doctrine leaving nothing out-conviction of sin, the reality of Judgement and Hell, free grace, justification, sanctification, glorification. We must also show that there is a world view in the Bible ... that here alone you can understand history-past history, present history, future history. Let us show this great world view, and God's Eternal purpose.... Let us at the same time be very careful that we are giving it to the whole man ... the gospel is not only for a man's heart, that you start with his head and present Truth to it ... Let us show that it is a great message given by God which we in turn pass on to the mind, to the heart, to the will. There is ever this danger of leaving out some part or other of man's personality... Let us be certain that we address the whole man-his mind, his emotions and his will.
D. Martyn Lloyd-Jones
Are you indeed Christ's sheep? Then beware of ever trusting to yourselves; nothing offends the Good Shepherd more than to see the members of His flock, forgetting that in Him alone is all their safety, and glorying in their own attainments and performances...your best attempts toward heaven are in themselves but broken reeds, and can bear no weight; they are precious as evidences of spiritual life--but they cannot justify.
J. C. Ryle
Preach the Gospel, and since its necessary, use words. Ed Stetzer
The Gospel, as it teacheth what is to be done, so it hath also the efficacy of the Holy Ghost adjoined to it, by whom being regenerated we have strength both to believe the Gospel and to perform those things which it commandeth.
What would not those poor damned, hopeless souls give for one day's opportunity such as you now enjoy? And now you have an extraordinary opportunity, a day wherein Christ has thrown the door of mercy wide open, and stands calling, and crying with a loud voice to poor sinners, a day wherein many are flocking to him, and pressing into the kingdom of God; many are daily coming from the east, west, north, and south; many that were very lately in the same miserable condition that you are in are now in a happy state with their hearts filled with love to Him who has loved them, and washed them from their sins in His own blood, and rejoicing in hope of the glory of God. How awful is it to be left behind at such a day to see so many others feasting, while you are pining and perishing! To see so many rejoicing and singing for joy of heart, while you have cause to mourn for sorrow of heart, and to howl for vexation of spirit! How can you rest one moment in such a condition? Are not your souls as precious as the souls of those who are flocking form day to day to Christ?