Again I have already answered this, why are you not reading what I wrote? If you don't accept, I am fine, but don't keep repeating your questions.
There was no gog before the dbr of Jesus. In the 4 gospel accounts, there was no gospel for the gentiles as Jesus was only sent to the Jews. The only gospel being proclaimed then was the gok. The bible clearly stares that no dbr was preached then.
Strange that you are making this into such a big deal. If you think about it, it made perfect sense to keep that revelation of the dbr was deliberately kept as a secret, a mystery that only revealed to the Apostle Paul. if that mystery was revealed then, Satan would not have allowed Jesus to be crucified (1 Cor 2:8).
8 Which none of the princes of this world knew: for had they known it, they would not have crucified the Lord of glory.
To me, it is clear. If Satan understood the divine exchange when Jesus was on Earth preaching, he would also understood that he could no longer use the law to condemn Christians who believe in the divine exchange, why would he deliberately cause his own permanent defeat by tempting everyone, especially Judas, to set the train in motion for Jesus’s crucifixion?
Isn't God's plan, in making revelation only progressive, great?
NIV1984 John 16:7-14
But I tell you the truth: It is for your good that I am going away. Unless I go away, the Counselor will not come to you; but if I go, I will send him to you. When he comes, HE WILL CONVICT THE WORLD OF GUILT in regard to sin and righteousness and judgment: in regard to sin, because men DO NOT BELIEVE IN ME; in regard to righteousness, because I am GOING TO THE FATHER, where you can see me no longer; and in regard to judgment, because the prince of this world NOW STANDS CONDEMNED. “I have much more to say to you, more than you can now bear. But when he, the Spirit of truth, comes, he will guide you into all truth. He will not speak on his own; he will speak only what he hears, and he will tell you what is yet to come. He will bring glory to me by taking from what is mine and making it known to you.
The GC is clearly not only for the Jews since the Gospel was to be preached to make disciples of all nations not just the Jews.
Paul's purpose and intention in preaching the Gospel was to lead the gentiles to obey God as was the message from the beginning which is to love God and one another.
NIV1984 1 John 3:11
Love One Another This is the message you heard from the beginning: We should love one another.
So the message of the Gospel either for the Jews or the Gentiles and even for the new creation IN CHRIST is one and the same gospel of LOVE.
NIV1984 1 John 3:16
This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers.
NIV1984 1 John 5:3
This is love for God: TO OBEY HIS COMMANDS. And his commands are not burdensome,
NIV1984 1 Corinthians 13:2
...and if I have a faith that can move mountains, but have not love, I am nothing...
NIV1984 Galatians 5:6
...The only thing that counts is faith expressing itself through love...
The message of the cross is SELFLESS LOVE.
The Gospel preached to the Jews speaks about OBEDIENCE TO GOD which according to John is what love is. Apostle Paul speaks of the same message when He said this;
"I will not venture to speak of anything except what Christ has accomplished through me in leading the Gentiles to obey God by what I have said and done—" Romans 15:18
NIV1984 1 Peter 2:8
"...They stumble because THEY DISOBEY THE MESSAGE—which is also what they were destined for.
NIV1984 James 4:7-12
Submit yourselves, then, to God. Resist the devil, and he will flee from you. Come near to God and he will come near to you. Wash your hands, you SINNERS, and PURIFY YOUR HEARTS, you DOUBLE-MINDED. Grieve, mourn and wail. Change your laughter to mourning and your joy to gloom. HUMBLE YOURSELVES before the Lord, and he will lift you up. Brothers, DO NOT SLANDER ONE ANOTHER. Anyone who speaks against his brother or judges him speaks against the law and judges it. When you judge the law, you are not keeping it, but sitting in judgment on it.
There is only one Lawgiver and Judge, the one who is able to save and destroy.
But you—who are you to judge your neighbor?