Let's examine how your "gospel" is ironically a perversion of the true gospel. You say Paul rebuked the Galatians for going back to obeying the Law, but this is clearly fallacious and illogical, lie as Gal. 4 and Paul's other statements to other congregations prove:
But then, indeed, when you did not know God, you served those which by nature are not gods. But now after you have known God, or rather are known by God, how is it that you turn again to the weak and beggarly elements, to which you desire again to be in bondage?" - Gal. 4:8-9
In this particular passage that is often misquoted by antinomians, Paul clearly mentions the Galatians going from a cycle of being involved in occult practices, to obeying God's laws, and then going back to the occult practices they participated in prior to their conversion. Considering the audience was at least mostly made up of Gentiles, It is both dishonest and illogical to conclude Paul rebuked the Galatians for keeping God's laws when they had absolutely no knowledge of the Law prior to their conversion. Paul specifically stated in Romans that the Jews were the only people had retained knowledge of the Law.
Here is how the Bible shows antinomians are shows to be purely absurd and self- deceived in their thinking. In Rom. 3:31, Paul says he and the other apostles were upholding the authority of the Law:
"Do we then make void the law through faith? Certainly not! On the contrary, we establish the law." - Rom. 3:31
Paul also told a primarily Gentile audience in Corinth that they should keep God's commandments:
"Circumcision is nothing and uncircumcision is nothing, but keeping the commandments of God is what matters." - 1 Cor. 7:19
Paul also told this same audience that he taught the same thing to all Christian congregations that God established under him:
"Nevertheless, as the Lord has assigned to each one, as God has called each person, so must he live. I give this sort of direction in all the churches." - 1 Cor. 7:17
According to antinomian logic, Paul told different congregations different doctrines, but the Bible shows it makes no logical sense to believe Paul would tell the Corinthians that they should keep God's commandments, tell the Romans that all of the apostles(including himself) were upholding the Law's authority, and then turn around and rebuke the Galatians around A.D. 50 for keeping the same laws he upheld and lived by. You tell people to know their bibles, but an often overlooked revelation in Heb. 4 shows why antinomians like yourself don't know the Bible(let alone what Christ's gospel was):
"For indeed the gospel was preached to us as well as to them(the generation of Israelites God rescued from Egypt); but the word which they heard did not profit them, not being mixed with faith in those who heard it." - Heb. 4:2
And there it is. Paul stated in no uncertain terms that the apostles taught the same gospel that was given to the OT Israelites when they received the Law. Moses did not preach a gospel that was different from Christ's or even antithetical to Christ, contrary to the delusions of antinomians.
In that same passage, Paul says hearing the gospel didn't benefit them because they refused to believe it and lacked real faith in God, and the same is true of antinomians today. They claim to love God and cherish the Bible, but they don't believe His prophets. And as Christ said in Luke, whoever doesn't believe the prophets are fools!