What is the Gospel Which a Man is Damned for not Believing?

THE gospel which you are commanded to believe, and which you will be damned for not believing, is “the gospel of God concerning His Son Jesus Christ our Lord” (Rom. 1:1-41Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God, 2(Which he had promised afore by his prophets in the holy scriptures,) 3Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh; 4And declared to be the Son of God with power, according to the spirit of holiness, by the resurrection from the dead: (Romans 1:1‑4)).
In Christ God has declared His LOVE. In the gospel He commends it (Rom. 5:88But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us. (Romans 5:8)).
What Christ was, God is; that is, God has been so fully declared in His blessed Son (John 1:1818No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared him. (John 1:18)), that the refusal of Christ is the refusal of the God who has thus, in grace and truth, so fully laid bare His whole heart.
Every moral excellence in the blessed God was seen in the man Christ Jesus. Hence the condemnation. “Light is come into the world, and men loved darkness rather than light, because their deeds were evil” (John 3:1919And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. (John 3:19)). It is the light of the revelation of what God is that has come in with the presence of the Beloved of the Father here below, leaving man without excuse. Nothing can more fully demonstrate the wickedness of the human heart than the refusal of Christ as the only begotten Son declaring what God is, because that declaration shows that God is for man, notwithstanding all the evil that is in him. “He that believeth not shall be damned.”
When a soul has bowed to the righteous sentence of God against him as a sinner, when he has bowed to the authority of Jesus as his Lord, all the blessings of the gospel are his; and it is of these blessings, with the responsibilities attaching to them, that the epistles mainly speak. These epistles, be it remembered, are not written to unconverted people, but to those who have believed in the Lord Jesus Christ as their Saviour.
I could not say, “Christ died for your sins if you believe He did.” I don’t think that is the way the gospel is presented. But when a person has come before God in true self-judgment, with broken-hearted confession of his guilt—when he has believed the testimony of God revealed in grace through Christ—I could direct him to the Spirit’s testimonies in the Scriptures as to all that righteously flows to him through the death, resurrection, and ascension of the Lord Jesus Christ (see 1 Cor. 15:1-41Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; 2By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. 3For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; 4And that he was buried, and that he rose again the third day according to the scriptures: (1 Corinthians 15:1‑4)).
Paul first directed the converted jailer to Christ Himself, and afterward spake unto him “the word of the Lord.” It is Christ Himself that we need to direct anxious souls to, and when in true repentance they have heartily bowed to God’s Raised One as Lord, then it is our privilege to show them what are God’s blessings in the gospel, as revealed by the Spirit in the Word for the acceptance and joy of faith, and to say, “All things are yours.” First the Blesser, then the blessing; without the Blesser no blessing.
The refusal of God declared in grace will get its own reward. The judgment that falls upon the head of a gospel rejecter will fall heavily. His silence at the bar of judgment will eloquently declare the righteousness of his sentence, how well-deserved his doom.
“He that is not subject to the Son shall not see life, but the wrath of God abideth on him” (John 3:36,36He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him. (John 3:36) New Trans.).
“The Lord Jesus shall be revealed from heaven with His mighty angels, in flaming fire taking vengeance on them that know not God, and that obey not the gospel of oar Lord Jesus Christ: who shall be punished with everlasting destruction from the presence of the Lord, and from the glory of His power” (2 Thess. 1:7-97And to you who are troubled rest with us, when the Lord Jesus shall be revealed from heaven with his mighty angels, 8In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ: 9Who shall be punished with everlasting destruction from the presence of the Lord, and from the glory of his power; (2 Thessalonians 1:7‑9)).
“He that believeth not shall be damned” (Mark 16:1616He that believeth and is baptized shall be saved; but he that believeth not shall be damned. (Mark 16:16)).
“See that ye refuse not Him that speaketh” (Heb. 12: 25).